I would like to be able to run all of my applications and have all of
my data available to me identically on the different computers that I
use. I hope that this may be achievable by having a *single* hard
drive that I can slot into (or connect via USB 2.0) to each different
computer that I use (e.g. various home PCs, laptop and work PC).

This would eliminate any data synchronisation issues and mean that I
don't have to keep updating software versions on each computer.

Please describe what under what circumstances this may be successful
and any issues that may arise. I realise that this would not work with
a standard version of XP, since XP is sensitive to hardware changes.
So assume I wish to run Windows 2000 or modified XP and that I have
sufficient licences to run the OS and all apps on each system.

Does anyone have experience running the same installation of
Win2000/XP on a laptop as well as a PC? Can the OS just reconfigure to
the new hardware environment when placed within it? Is this
reconfiguring a slow process each time the hard drive is moved between
the computers?

If the above is not really feasible, what is the best alternative to
get the same apps and data on a home PC, a laptop and a work PC as I
use each (one at a time).

Only microsoft knows that answer if it were possible at all.

If you are willing to try FreeBSD, this is definitely feasible. I do
this at home and at work everyday. Works on PCs and laptops, wired and
802.11. If you really want to run XP, consider running it under VMWare
through FreeBSD.

I would not recommend you doing it alone if you have no prior exposure
to FreeBSD. Try installing it on one of your machines and use it for a
while.

Briefly, you need to do the following:

1. Pick a PC with disks to be your FreeBSD file server. I suggest you
install the OS on one disk, and have a separate large disk to host
your home directory and data. This way you can wipe out the OS disk
and upgrade to the next version quickly and safely. Leave it running
24x7.

2. configure your file server machine to serve DHCP and NFS.
3. the instructions below describes how to prepare a root file system
for the diskless clients.
4. boot your clients with a floppy via etherboot
(etherboot.sourceforge.net)
5. if your client machine does not have a floppy drive, use intel's
PXE boot agent found on most recent intel 100pro cards. lots of
laptops have these cards builtin.
6. if you dont have a bootable ethercard, you can still make it work
by booting off a CD.
http://www.bsdtoday.com/2002/March/Features646.html

7. dont forget to backup your data. Buy two identical disks, use one
on the server, and backup the whole drive with the second disk.

Get detailed diskless boot instructions from here:
http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/diskless.html

security concern:

NFS is insecure. you need to put your machines behind a firewall.

Easy one.  As long as the other machine doesn't have a hard drive in
it yet, you just buy a hard drive 20 GB or so and load everything on
that you want.  Then just purchase one of these:
http://www.regularprice.com/525cdcddvdex.html
And then you can use USB to connect it.  Just like you want.

The device shown above will most likely not work for you. The problem
with using a USB drive is that you will need to install driver to tell
the computer how to accsess the drive. Newer operatiing systems like
XP might have these drivers pre-loaded, but thats a moot point if you
need to accsees the drive BEFORE the OS. (as in booting off of the USB
drive) Furthermore, i have personally never seen a computer that has
an option to boot from a USB device.
For your home and work PCs, a removable hard drive bracket seems like
a good soulution. you would simply install 98, ME, 2000, on the
computer, then enable a feature called "hardware profiles". Window's
help has all the info on hot to do that. Basically you would have a
different set of drivers loaded for each sytem, and choose among them
depending on which computer you are at. How well this acctually worksd
in practise i can't say, as i have never done it, but it seems
straitforward and simple.
As far as your laptop goes, its far more complicated. laptop hard
drive connect in a physically different fashion than desktops. ive
seen connectiors to go from laptop hard drives > destop computer, but
not vice versa. It is however, depending on yuor compfort level
possible to reverse-engineer one of those connectors into using a
desktop hard drive for your laptop. the problem then becomes "what do
i do with this big hard drive that wont fit in my laptop, and how do i
power it?" you would have to sacrafice portability. also, you would
have wires coming out of the laptop. the standard connector (40pin
IDE) is not made for day to day changing, and would wear out quickly.
you could make a custom converter using an old 36 pin printer cable to
connect it instead. i have even seen the aformentioned hard drive
brackets using them. that would be great, because you could plug the
hard drive cartridge into your custome connector on the laptop.
Another possible soulution would be to keep the laptop hardware as is,
and use a program like "desktop DNA" to migrate your settings and
application from one computer to the next. i would recomend a network
connection beetween one of your boxes and the laptop to pull that off.
As you can see, the laptop wildcard really complicates this issue.
The desktop situation is easy, and routine. Additionally i should
mention that windowsXP PRO does not use the hardware signature, and
CAN be used on more than one machine. weather or not it MAY be used is
a different story. If you got liscencses, it's definatly not a
problem.
If you like having the best compatability with ~90% of available
applications, stick to microsoft OSs. besides, FreeBSD is not like
windows, and i dont get the vibe that your wanting to learn (and
maintain) another OS, just to have accomplish your goal, especially
when its easy to do with windows, and cheap hardware.
check out pricewatch or something and search for "removable bracket
ide". im sure you can find something.
if i am not being clear on something, let me know, and ill try to help
you out.
-goodluck

The best method for you would be to setup a computer for just the
storage of data files (such as documents, pictures, etc).  This
computer would also act as an ftp server.  If you networked all your
computers together you could get great speeds (100mbs) when sending
and receiving files.

So basically what you could do is ftp all your data to the computer
acting as the ftp server, or if you prefer a different approach, you
could use a backup source such as jazz drive or something similar to
transfer and recieve files on your other computer.

The good thing about creating an ftp server is that it can be made
accessible through the internet, which means you can access these
files outside your normal working area (especially with the laptop).

For ftp servers you could use servu for windows, or if using a unix
you could use pureftpd.

hope that helps...

Thanks very much for lots of useful information ogagoo-ga.

I'll definitely check out the 'hardware profiles' feature that does
also seem to be a part of Windows XP Pro. I'm interested that you say
that XP Pro "does not use the hardware signature" - I'll be keen to
find out whether it's fine about *all* of the hardware changing under
a different profile...

As for hardware, you hit on the main issues that I was considering. A
2.5" laptop hard drive could be used everywhere, but then performance
would be sacrificed on the desktops that are used most of the time.
I'd guess that the performance of best laptop hard drive doesn't come
close to the best IDE desktop hard drive.

The other solution would be to use a 3.5" desktop hard drive
everywhere, but then we get the inconvenience problem when using it
with the laptop. Apart from being bulky, the drive is going to need
power, and to be connected to the laptop somehow. I would hope that a
FireWire enclosure for the 3.5" drive would do the trick. This would
the 6-pin version of firewire, so that the laptop may power the hard
drive. But I guess that a 3.5" drive would be a big power drain on a
laptop.

Then there would be the issue of booting using the FireWire drive.
It's easy on a Mac, but how about a PC?... I wonder if a
boot-to-FireWire floppy might exist? That would be ideal considering
the lack of such an option in the BIOS.

A third hardware solution would be to use a nice compact FireWire or
USB 2.0 external hard drive. But then a booting solution must be found
for all of the computers!

Thanks for all the comments.

I do this with VMWare and a removable SCSI drive. All my machines are
reasonably fast, so reduced speed due to virtualizing the OS has not
been an issue. If you are running CAD or DirectX games, that might be
a problem though. Getting two VMWare licenses is a little pricey
too--work paid for mine.

VMWare runs a fake PC inside a window (which can be fullscreened,
giving the appearance of a normal machine.) You just install VMWare on
each machine already running Windows or Linux, and load the VMWare
"virtual PC" from a file kept on your removable drive. Fullscreen it,
and you won't know the difference.

I suspect a really basic linux install running only VMWare could
reduce VMWare's overhead even more. I've had no experience with this.

quick tip:
if your worried that XP wont like changing all the hardware, you can
solve the problem at the source.
To detect the hardware changes for liscence compatability, XP utilizes
and internal service called "Shell Hardware Detection"
disable this, and it wont know where it's running.
goto controlpanel>admin tools>services.
a list of about 20-40 things (depending on your install option) will
appear.
doubleclick "Shell Hardware Detection"
change "startup type" to "disable"
CLICK APPLY, THEN OK
reboot
now, you can "pull the rug out from underneath" at will

also, you might want to checkout a free MS util called "sysprep",
which resets all of the hardware on the installation, and forces new
hardware detection upon the next boot.
coupled with the roll-back features, you might be able to quickly
switch between the two.

- also you dont mention the laptop type, but if it can boot off of the
network, you could purchase a ethernet > IDE case for the drives. they
make any drive NAS. and boot from there.

- a quick search did not reveal any firewire boot options for PCs.
mayby with linux you could gain access to the drive, and then somehow
"hand it over" to windows? i dont know if that would work or not. but
i belive its possible.

i hope this help you out
feel free to post more questions, and ill see what i can do.

As a clarification to the above XP hardware detection trick.
i do not offically condone this feature be utilized for infringing
copyrights, or violating your liscence in any way. if in doubt, check
with microsoft for lagallity issues.
;)
Besides, youll still have to activate it.

Few thoughts here:
First, Windows XP Pro DOES perform activation checks. The only
versions of XP that don't are corporate licensed editions (like
through Software Assurance). This is because at the licensing level,
it becomes unfeasible to track which license for each program is with
each system. It becomes a matter of, OK you have 25 PCs running
windows XP Pro and Office XP and Photoshop. You purchased 30 licenses
for Windows and Office, so you're fine there, but you only bought 20
photoshop licenses, so it can only be installed on 20 systems.

Next, even if the hardware work-around trick listed below did work (I
don't know if it does) I'm sure that MS would/will soon patch it so it
won't work. I;m also pretty sure that not only would it be in
violation of copyright and/or patent laws, leaving you liable for
civil lawsuits and fees, but you would also be in violation of your
license agreement, leaving you open to more fees. In fact, it's
probably also a violation of the American DMCA, which means you, the
person who posted the info, and google would be facing possible
CRIMINAL charges and jail time. (unless you're not in the US, in which
case you're safe as long as you don't enter the US. Think Dmitri
Sklyarov.)

Next, hardware profiles. These were originally intended to allow
notebooks to switch easily between the drivers needed when docked to
the drivers needed when undocked. I can't see it working well for a
completely different system.

Same goes for just installing all the drivers and letting Windows
figure it out when you boot. Cludgy and can lead to problems, and
corrupted files/drivers.

FreeBSD is a kinda complex route.

Same for jury rigging a connector for the laptop drive to connect to
regular IDE. Best way to do this would be to install a drive caddy in
your towers, and then use the 2.5 to 3.5 kits to put your laptop's
internal drive into the tower when needed. Still non-ideal.

I agree fully with the problems booting from USB/firewire drives.

My suggestions:

1) Install OS and Software and Settings on all systems. In XP, you can
use files and settings transfer wizard to copy settings over. Keep
data files on public server (i-drive kinda thing) and access them from
each PC as needed.

2) Pick one system to be the "base" system. Have Windows XP Pro and
all application installed on it. THen use remote desktop connection to
conenct to it from almost any other computer (inlcuding Win 9x, ME,
XP, 2000, pocket PC 2002 and Mac OS), see your desktop, and un your
programs and access your files (PC anywhere kinda deal.) I use this to
access my files and programs at home while I'm at work. Works quite
well. Even allows use of printers over the connection.

3) A little tricky. Use a removable drive (either USB/firewire, or a
PC Card hard drive with a reader for the towers) to store your data.
Install each program on each PC, but keep all of your data on the
removable drive. You could also install your software on each PC, but
in each case specifying the removeable drive as the install location
(as long as the software is installed into the same path, like
l:\apps\office\, then it should just overwrite the files with the same
files. ) You could then connect the removeable drive to the computer,
run office, and it would know that it was installed in l:\apps\office\
or whatever. Then only the OS need be installed on the main drive in
each system.

4) The vmware idea is really cool. Get a removeable drive (firewire or
pccard or usb2 preferred. Have a vmware partition with windows XP on
it. boot into that from whichever PC you want. The hardware drivers
shouldn't change since they're emulated. ie. Vmware CD-ROM is always
VMware CD-ROM. You may want to copy the vmware virtual drive over to
the local hard drive, and then copy it back to the removable drive
when you're done. Better performance that way.

Sparky4ca

Instead of trying to boot up two computers from one HDD, I would
suggest purchasing a docking station for the laptop.

Well now, this is getting interesting. Thanks for everyone's comments
- they have all been helpful.

I thought it would be useful to summarise where we've got to. Ok, in
terms of the OS/software side these are the main possible solutions,
along with their main drawbacks:

1) Hardware Profiles
-xx will this work when moving the OS between different desktops and a
laptop??

2) VMWare
-xx slow
-xx extra long bootup time
-xx is XP reliable and full-featured under VMWare?

3) PCAnywhere etc. (One main PC that allows for a remote desktop)
-xx slow (latency and screen update problems)
-xx inaccessible from the laptop when travelling
-xx insecure

4) Separate OS and app installations that are synchronised
-xx requires synchronisation (time-consuming, inconvenient and error
prone)

Sorry that I only point out the problems! They are all great ideas & I
hope that one of them may be workable.

Ok, and now the hardware choices (for 1 & 2 above):

1) a 2.5" laptop drive slotted into the laptop or desktops (using
enclosure)
-xx slow

2) a 3.5" desktop drive slotted into desktops (using enclosure) and
connected by USB 2.0 or FireWire to the laptop
-xx how can one boot from USB 2.0 or FireWire without BIOS support?
-xx may wear out the drive connectors
-xx major power drain on the laptop?
-xx inconvenient & bulky for laptop use

3) a USB 2.0 or FireWire external drive connected to the laptop or
desktop
-xx how can one boot from USB 2.0 or FireWire without BIOS support?
-xx always going to be slower than an internal 3.5" drive? (is this a
limitation of the interface or the external drives that exist?)

Well that's where we stand now. Thanks again.

ok few few points quickly
1 good summery of options. that needed to be done.
2 the hardware trick does work, but only XPhome checks anyway
3. i pulled this from the XP EULA, right from the cd;
starting at section 4- 
"4. TRANSFER-Internal.  You may move the Product to a different
    Workstation Computer.  After the transfer, you must
    completely remove the Product from the former Workstation
    Computer."  it goes on to talk about transfering to third party.
Now, for the sceneario of using the samme boot hd; pulling it out of
the computer would most certainly be considered a "completely remove
the Product from the former Workstation Computer. so, as long you you
activate it, which i assume you will, legally, you should be fine.

> 1) a 2.5" laptop drive slotted into the laptop or desktops (using
> enclosure)  /  -xx slow 

Actually, you'd be surprised at how well current laptop hard drives
perform. At my previous job, I ran a test against a Firewire/USB 2.0
external enclosure we manufactured and a 3.5" hard drive.

The laptop drive won by a surprising margin compared to a UDMA/33 3.5"
5400RPM hard drive. The scores would probably change if you were using
a PCI ATA-100/133 controller or something, but by the time you're
using that, you're elbowing into SCSI level performance anyway.

A laptop drive in a high quality Firewire/USB 2.0 enclosure will work
well for general use; the throughput is limited by the speed of
Firewire/USB 2.0, not by the capabilities of the drive.

> 2) a 3.5" desktop drive slotted into desktops (using enclosure) and
> connected by USB 2.0 or FireWire to the laptop
> -xx how can one boot from USB 2.0 or FireWire without BIOS support?

You cannot. Many newer systems do support booting from Firewire and/or
USB devices, but many do not.

> -xx may wear out the drive connectors 

Should not be a concern. Reliability is often a concern with those
enclosures, however. Most are relatively flimsy and unreliable, in my
experience. (The same goes for those "hotswap IDE docking bay" things
you can pick up anywhere for $20. They're not good if you like to keep
your data intact.)

> -xx major power drain on the laptop? 

A laptop can not and will not power a 3.5" hard drive over Firewire. A
laptop will struggle to power a 2.5" laptop drive over Firewire.
Obtaining an enclosure that has its own power supply would be STRONGLY
recommended if going this route. The good ones will come with their
own power supply, anyway. You'll kill your laptop battery in no time
flat running an external drive enclosure.

> -xx inconvenient & bulky for laptop use 

No arguments here; the 3.5" enclosures are too big to cart around a
lot. There's laptops smaller than some of them.
 
>  3) a USB 2.0 or FireWire external drive connected to the laptop or
>  desktop
>  -xx how can one boot from USB 2.0 or FireWire without BIOS support?

Can't be done without BIOS support. Period. Prior to loading the
operating system, BIOS is the only factor in deciding anything. If it
has no option to boot from Firewire or USB, then it cannot be done on
that system. A BIOS update for the system may add this functionality
if you're lucky and the motherboard/system manufacturer is good about
adding functionality to existing product lines.

> -xx always going to be slower than an internal 3.5" drive? (is this
a
> limitation of the interface or the external drives that exist?)

You won't notice a performance difference between a laptop drive in an
external IEEE1394 enclosure and a desktop drive in an external
IEEE1394 enclosure. Both drives outperform the data throughput
capabilities of Firewire and USB 2.0. (Firewire would be better for
sustained data throughput. USB 2.0 is better for burst data
transmissions, but is slower for streaming large amounts of data,
despite its higher theoretical maximum.)

One more note about the external enclosures -- you want an Oxford chip
in the enclosure's interface board. There are a few different
manufacturers of the interface board chipsets, and Oxford is the one
with the most reliable performance of the lot. When I was working with
these products, the Oxford 911 chip was the king of the hill. They may
have something newer at this point; it's been several months since I
worked with these devices, and I haven't kept up on the latest news in
that corner of the world.

ok few few points quickly
1 good summery of options. that needed to be done.
2 the hardware trick does work, but only XPhome checks anyway
3. i pulled this from the XP EULA, right from the cd;
starting at section 4- 
"4. TRANSFER-Internal.  You may move the Product to a different
    Workstation Computer.  After the transfer, you must
    completely remove the Product from the former Workstation
    Computer."      it goes on to talk about transfering to third
party.
Now, for the sceneario of using the samme boot hd; pulling it out of
the computer would most certainly be considered a "completely remove
the Product from the former Workstation Computer. so, as long you you
activate it, which i assume you will, legally, you should be fine.

4. i dont know it the hardware profiles will work or not, ive never
tries. But, if it does what it says (and thats a big if for MS), it
should do just fine

5. a possible way to speed up the portable 2.5 drive, would be to use
2 of them, and software RAID(0) them in XP. this would be almost as
fast a desktop drive of the same capacity., and much less power,
noise, and heat. tricking XP into booting from this might take a boot
floppy or cdrom. but it can be done.

6. XP (or anyother mention of an OS for that matter) is not found
anywhere in the DCMA

7. PC anywhere performance is primarily a refection of bandwidth
(read: network speed). its decent on a 100base, and on 1000base, its
almost as good as bieng there(fast+fullcolor). i have a little server
in a cardboard box with a 100, and use pcanywhere to change settings
and what not. i would play anygames overit, or cut amautuer movies. i
dont know what you use it for. if its to play mp3s or something, its
not a problem. you could do a barebone windows install, and have it
automatically start into pcanywhere full screen. buy a couple of 1000
cards for the full effect. although that still leaves your laptop out
in the cold.
8. vmware works. not perfect. but id imagine it really depends on who
you ask. rose colored glasses kinda thing. ill point out that even XP
isnt perfect, nor is linux (despite claims), and a chain is only as
strong as the weakest link. plus, more overhead, booting, possible
conflict of some sort.... but i bet it could be done, and with enough
tweaking, in a fairly satisfactory way.

9. you could have another externat battery for the portable 3,5 drive.
its usually either 5, or 12 volts or in the cast of ide, both. but
that again makes another thing to carry.
10. i did more digging looking for firewire or usb2 boot options. no
such suck. bios definatly not, and i could find any boot disk info,
which is not encouraging. maybe thats something that might come about
later. its a bad-ass idea though, and i hope someone does it.
11. maxtor portable usb2+fire wire drives are not bus powered, and
require an AC adapter to be used. i dont know about other brands.

12. the interface is the speed limitation. there are regulat IDE
harddrives in the enclosures. (i demantled an 80 gig one last week.
did have to reformat, then it worked fine)
13. the best advice is free advice. lol even still i think youve
already gotten 4 bucks worth. dont you? or nothing, as i look again.
thats great! i should ask stuff.
14. you could run demo linux and boot from a cd everytime. save the
files on a removable low power usb, or pcmcia compact flash card.
(slow to boot, really good after that)
15. another possibility not yet even considered. using a powered,
amplified KVM stwitch. is your latops good, you could always use it.
use the keyboards and mouse  from the other room. like a hardware
superfast pcanywhere, that doesnt fail. if you laptops not that great,
host from the best desktop. that way, they will be identical. becasue
its that same computer. you also get a bonus tower out of the deal. it
could probably pay for most or all of the kvm.
the video does break down depending on how hfar you want to run it.
good cables, and amplification should let you go several yards though,
and they make repeater for the middle if that not enough. do a google
search about powered KVMs. you have to do something like syncing if
your laptop sucks, but 2 outta 3 aint bad.

------
what i noticed, is that there is no perfect soulution.
no matter what route you take, a compromise must be made because there
is no off-the-shelf soulution. there are probably about the best ideas
around above here. i suggest you review your list, and critically
think about which opitions are more important to you. consider what
you use these computers for, and which compromise affects this usage
the least. i dont think youll find a way to have it all. no one
soulution will be completly workable. its like asking for a car that
does 0-60 in 4 secs, get 75 MPG, tows cattle, and never breaks down.
Whatever you decide, i hope it works ok for you, and doenst drive you
mad.

post any other ?s.

one more easy way (but not perfect way) have different hard drives on
everything. everythings  aseperate computer boot and all. user
tweakui, or some other XP customizer to change your mydoucments folder
to a removable drive. flash or usb2 HD, etc... you still have to
double install apps, but the docs are the same always. again a
compromise, but easy and cheap!

an operating system wouldn't need to be mentioned specifically in the
DMCA. The act of attempting to circumvent the copyright of the OS, as
a copyrighted work, could be seen as violation. Don't risk it.

Although using the same hard drive in both should meet the terms of
the EULA, you'd still be stuck activating. and reactivating.