I have two separate computer questions for problems that are going on
with two separate computers.  What I am trying to get a sense of is
what the problems are and how much they would be to get fixed if I
took it to someplace like Best Buy.  If someone knows how I could fix
these problems myself that would be great as well.

Problem #1: This is a two-year-old no-name computer I bought new off
the internet. (I'll never do that again.)  Its processor is an AMD
Athalon 750mhz and it has a 10-gig hard drive.  It has always worked
fine until about a week ago when it spontaneously started turning
itself off.  After about 20 minutes the computer will just completely
shut down.  It I immediately try and turn it back on with the button
on the front of the tower, nothing happens.  To turn it back on I have
to wait about a half hour and then turn the switch on the back of the
computer off and then on again before it will power up with the button
on the front.  My thought is maybe its overheating and blowing a fuse
or something, but I don't know computer hardwars so...  I took off the
outer cover and tried to vacuum out all the dust I could, but that
didn't have any effect.  I have run a total system virus scan and it
scans clean.

Problem #2:  This computer is and HP Pentium 2 that is almost
four-years-old.  It recently started making this high pitched squeal
whenever it is on.  It is not very loud, but it is definitely
something that everyone can hear when they walk into the room.  This
computer also is free of viruses.

Thanks for the assistance.

Hi Needsomeinfo,

Thanks for your question. I'm not an engineer, but I'm very familair
with these brandless computers and all the problems that can occur.
From your question I'm quite sure what the problem with your first
computer is, a little bit less in the second case, but I hope my
experience can help.

1. I think your idea is right: the computer, and most likely your CPU
is overheating. This part produces most heat and has a little fan to
cool it. WHen the fan is not working, the CPU get too hot and stops
working after some time. It might even make nasty noises. When you
stop (or have to stop) working the CPU cools down, and after some time
you can start again.
You might try to get the fan working manually again, but the best
thing is to replace it (or get somebody to replace it). The fan is
very cheap to replace, while your CPU might be rather expensive.

2. This sounds even more serious. When I hear my computer making
noises, I right away save all my crucial information from the hard
drive. I know I should do this on a regular basis, but an uncommon
irrirating sound means something is about to collapse and in most
cases it is going to be you hard drive.
While I would be able to replace a fan (problem 1), I would always get
some expert friend in to look at this kind of problem.

As you say, it is very unlikely that virusses are causing any of both
problems: it is your hardware.

Good luck.

Fons

Not a bad answer, but some of the comments were much more thorough and
helpful.  I realize that it is difficult to diagnose compter problems
after a brief description.  A special thanks to sparky5ca.  Your
answer was very helpful.  It helped me figure out how to diagnose my
own computer.

Start by removing and reinstalling new power supplies in both the
computers.  Then you won't have to deal with the squeal in your ear. 
Also your posing a safty hazard by running hot fuses.  That should
take care of problem two.  If problem one did not correct itself at
this time check the connections.  Start with the connection to the
floppy drive, then any cd-rom you have attached.  Go ahead pull the
plastic connectors apart;  your computer will not break.  Next check
the connections to the different hard drives.  Note to self:  Does the
fan on the processor turn?  Do I know what the bios is?  Must get
upgrading and repairing PC magazine, hmmm.  Now if the computer
doesn't pass your inital wiring inspection (and you did troubleshoot
it didn't you... like unplug a cd-rom and try a boot;  it either does
or it doesn't.) you have the choice of purchasing some new ram, go
ahead break the bank it is very inexpensive.  On the tenth day of
Christmas if that ram don't work and the bios settings do not change
anything get some Linux and chuck the "windows virus" out, or at least
run the poor defenseless machine behind a decent operating system.  Oh
and you are using a surge protector are you not?

ok you got some bad information, problem # 1, its 2 years old, power
supplies go bad at exactly that time (especially when they are cheap
ones) get a new one for 20 bucks online

problem 2, squeaky fans, not a big problem unless its a cpu fan, which
is about 15 dollars

cost for a professional to do the job, probably about 30-50 dollars,
its extremely easy work. hope you can find someone honest to do the
job

On #1 I agree too: replace the power supply first. This is a fairly
cheap first-step that may save you trouble and expenses later on.

On #2, the following may sound silly or may not apply, but I must ask:
are you sure it's the CPU making the noise and not, say, the monitor?
Have you tried turning the monitor on and off? If it is the CPU,
depending on the loudness of the sound, it may actually be a heat
alarm.

Have you moved either or both computers lately? Changed anything about
their environment? Is it particularly hot? Have you changed anything
about their electrical setup (new power supply or power strip?
anything else like that?)

Just some additional questions you may wish to ask yourself, if you
haven't already.

--Maggy

Mostly I agree with both the answer and the previous comment. The
first computer is overheating the CPU, since its starts again, and is
able to run something like a virus check, we can assume the CPU is
probably fine right now, but the fan is probably shot. Or the power
supply is over heating.

You've already taken the cover off this one, so take it off again and
start the computer. You should see a small fan sitting on top of the
CPU which is about 1 1/2' square. See if that is turning. If not, have
that changed. Very inexpensive and much less than a CPU.

If it is spinning then you probably have a Powersupply problem. A
little more expensive, but not much.

Your second computer, the wine, is from one of two things, your hard
drive or your powersupply fan. The power supply is a large sqaure,
probably silver looking box near the back. Looking at the computer
from the rear, you will see a fan there. If the noise is coming from
that, have it replaced.

If not, and you know how to take the computer case off, and it won't
invalidate your warrenty, then take that off and see if you can "hear"
what part of the computer the squeal is coming from, probably the hard
disk. The hard disk has a wide (about 2") flat cable going into it. If
that is the case, then your hard disk is going to go out soon. Back up
all your doc's and information onto a few disks, if you have a CD
burner this is better, and take it in for a new hard drive. This could
be more of a cost. Good disk can cost 150.00 US or more and its about
an hour's time for a tech to do it for you. Could be longer if you
need then to reload the OS for you.

Good luck. 

webadept-ga

The spontaneous shutting down problem, I'm willing to bet that it's
the power supply. I've had the exact same problem before, and I
couldn't figure it out. I replace the power supply, and boom. All
fine.

I work as a technician. I'd like to offer some advice here. Most of
the comments and answers are quite accurate. I'd ignore the advice
given in the very first comment.

**NOTE: Before performing any work inside the computer or handling any
computer components, be sure to ground yourself. Either hold onto the
metal of the case, or preferably pick up a grounding strap at the
local computer shop. Also never touch components in the computer while
it is plugged in.**

Now, for the first computer:
This problem is quite likely the power supply, although overheating is
defineatly a possibility. When your computer boots up, you should see
a phrase that reads like "press DEL to enter setup." That's press the
delete key, not your neighbour's Dell computer <grin>. Do whatever it
says to get into the setup (BIOS) screen. Every BIOS is a little
different, but basically if you have a blue screen with 2 columns of
yellow options, go into integrated peripherals and look for some lines
regarding current temperature and fan speed. if it's not there, go
through each other category until you find it. If you BIOS has instead
a white screen with a menu along the top, one of the menu choices has
"hardware monitor" as the very last item. Select it. If you BIOS is
different, then you'll just have to find the hardware monitor
yourself. sorry.

Once you have found it, take a look at your CPU fan speed. It should
usually be around 4,000 RPMs. also look at your CPU temperature and
systemboard temperature. According to AMD the maximum for these should
be 90 degrees CELCIUS for the CPU and about 42 degrees celcius for the
system. Realistically, you should see them around the 30-60 mark for
the cpu and 20-40 mark for the system. If the temperatures seem OK,
then watch them until the system dies on you.If they don't seem to get
super-hot then your processor probably isn't overheating. If you start
to see a rise in the temperature, and it seems to keep rising, then
you probably need to have the fan/heatsink either replaced or reseated
with more grease. If the fanspeed is low, or is fluctuates greatly,
that would be a clue that you need a new fan. If the fan is running
fast and reliably, but you still see the CPU heat go up lots, then the
heatsink probably isn't making good contact. Don't continue to run the
system until you get it fixed, as too much heat can damage the CPU.

If the CPU fan and temperature seem OK, then you need to find out what
else is causing the problem. Check all the wires, cards, etc in the
computer. Make sure there are none that are loose. If problem
persists, then try another power supply. Your local clone shope should
have them cheap. remove all the power plugs from everything in the
computer, remove the 4 screws at the back that hold the power supply
in place, and take it in to the shop. tell them you need a
replacement. Try to buy it somewhere you can return it to if it
doesn't solve the problem. Remount the power supply and reconnect all
of the cables exactly as they were before. Test it. If it still
doesn't work, You may have a more serious problem. You should take
your computer in,

Second computer
you'll need to open the case for this one. try to isolate with your
ear which of the following the sound seems to be coming from:
a) monitor (yes, it could be!)
in the computer:
b) cdrom drive
c) hard drive - mounted near the front of the case. will have a cable
similar to the flat cable attached to the cdrom and floppy drives
leading into it. will either be mounted directly above or below the
floppy drive, and all you'll be seeing is the right hand side of it in
the cage, or it will be mounted vertically at the bottom front of the
case, so you'll be seeing the entire front or back of the drive.
d) CPU fan - may be hard to locate in the HP, but should be in roughly
the same place as the cpu in your first system. Sometimes you get
noise if a cable is rubbing against the CPU fan. In some HPs, instead
of a cpu fan, there is a vent tube above the cpu that contains a fan,
the tube is directed to vent air out of the PC.
e)power supply - located at the top back of the case. should be
blowing air out.
f) something else.

resolutions for each problem:
a)get a new monitor
b)get a new cdrom drice
c)copy all of your important documents and downloaded stuff to floppy
disks or CDs if you have a burner. If you don't have a burner, and you
have too much critical stuff to copy to disks, then take the computer
to a computer shop. If the hard drive is whining, it needs to be
replaced ASAP. If it is the original drive, then there won't be any
warranty on it (unless you bought extended). If it's a newer drive
that you bought, there may be warranty. At any rate, you're going to
need to ask the computer shop to "GHOST" your drive, either to CDs or
to a replacement hard drive. good luck!
d)if it's the CPU fan, it either needs to have something that's
rubbing it moved away, or it needs to be replaced.
e)if it's the power supply, replace it. HP cases are harder to work
in. you may want to hve this one replaced at the computer shop.
f)consult with a local technician to be safe, but the component will
probably need ot be replaced.

i hope this has been helpful. Please let us know what the resolution
is.
PS. When virus scanning, please make sure you have virus definitions
that are less then one week old, otherwise you'll miss a lot of virii.

I'm pretty sure that the google answers person is incorrect, but it's
hard to diagnose things from what people tell them.

Problem 1 sounds like a power supply problem. Although your power
supply could be shutting itself down to avoid overheating, I've never
heard of that happening and have only heard of power units shutting
down due to internal problems which generally trip a circuit breaker. 
Most circuit breakers will not reset until the power supply is
removed, hence the reason that you have to use the power button on the
back of the computer that you were talking about.

Power supplies have never costed me more than $70 and that was for a
really good ATX power supply with lots of outlets, you should be able
to get a good one for a lot less than that.

Problem 2 is probably the CPU fan. Fans have bearings so that they can
spin freely and when fans go out the bearings are generally the first
to go and they usually make a squeaking noise.

CPU fans should be around 20 bucks.  Stop running this computer until
you replace it, you don't want to overheat the CPU, you'll damage it. 
I agree with the person that said to take the cover back off and look
at the CPU fan and see if it's spinning when you turn it on. You
should also be able to tell if that's where the noise is coming from
or not (you could use a static electricity grounded instrument to
physically stop the fan from spinning momentarily and see if that
stops the noise from occuring).

Be sure to always keep your body grounded while working on your
computer in order to prevent damaging your computer components with
static electricity charges that your body builds up which you will be
completely unaware of.  It takes a shock so small that you can't even
feel it in order to completely destroy computer chips, so be careful
in there.

As for "no name brand computers off the internet", one, your computer
lasted two years and this is the first problem you've had? That's
pretty damn good! Most computers are dead by two years, you obviously
got a good buy.

You couldn't pay me to own a preassembled name brand computer such as
Dell or Gateway and ESPECCIALLY not Compaq or Hewlett Packard.  The
only way to go is to custom build them. Next time you buy a computer,
find a friend that knows how to slap together computers (it's only
about as difficult as assembling a barbecue from sears) and get all
the custom components, and give the friend a case of beer or some cash
to help you pick out which components and software you need for what
your going to use your computer for and you will be garunteed to get a
computer for a hell of a lot cheaper than a fully assembled one from
the store without all the advertisements installed on your computer
and prebundled software that they put in there that you never use, and
it will be fully upgradeable if you get a good tower, unlike Hewlett
Packards and Compaqs which hardly ever even come with empty slots for
extra cd drives any more.

If it shuts down after exactly 20 minutes every time, then the likely
cause is probably the power saving settings in Windows.

To disable:
1.  Right-click your desktop
2.  Select "Display Settings"
3.  Click the screensaver tab
4.  Click the power settings button, near the energy star logo
5.  Change the settings for turning off hardware ("turn off hard
drives", "turn off computer") to "Never".
6.  Change the settings for standby/shutdown/hibernate to "Never"

When all of the drop-down lists on the page read as "Never", click
"Ok".  If the cause of your troubles was power saving, your problem
should go away.

Hi,

You've already received a lot suggestions, but I thought I would offer
a few more.  The first rule in fixing a computer is figure out what is
wrong before you start buying new parts and replacing them.   A sure
way for you to waste your money and your time is to replace something
before you know if it has gone bad.  This means that you should ignore
all those who told you to go out and buy a new power supply right
away.

For the first problem, I think that your CPU is overheating, as others
have said.  Many computers have features that shut off your computer
if the speed of your fan on your CPU becomes too slow OR if the
temperature of your CPU gets to high.  I believe that one of these
things is happening.  First, take the cover off of your computer case
just like you did to dust out the inside.  Next, with the cover off,
make sure that you can see the CPU and its fan and then turn the
computer on.  Check to see how the CPU fan is running (there might be
more than one fan on the CPU and they all need to be running) -- if it
is has gone bad it either won't be moving at all or it will be moving
in a really jerking motion.  If it is running correctly, you should
barely be able to see the fan moving and it should be running
smoothly.  If the fan is not working properly, you need to replace it.
 Go to a local computer shop and have them replace it for you.  If you
feel comfortable replacing it yourself, just tell them what kind of
CPU you have and its shape (Athlon's come in different packages
depending whether it's a Thunderbird or an original Athlon and you'll
need different fan's depending on the type) or discribe the original
fan.  If your CPU fan was running correctly, then you may want to
check out the power supply.

For the second problem, again, you want to find out exactly what is
wrong.  I would do something like I told you to do on the first
problem.  Take the cover off and try to find exactly where the
squealing is coming from.  Your best bet again is one of the fans (CPU
fan, power supply fan, etc.)  because those are moving parts inside
your computer.  If you locate the problem, great, either replace the
fan or the power supply.

I hope a gave you a few more options,
analogkid-ga

Some interesting answers, but one or two other possibilities.

The first sounds like overheating.  However, does it switch itself off
20 mins after it is first switched on in the morning, or does the
problem get worse as the day goes on?  If the latter, it could also be
the motherboard.  I had that problem and replacing the motherboard
finally fixed it.  It would also be worth checking the CPU fan to make
sure it is a) sufficient for the task and b) fitted properly and not
damaged.  Finally I take it that there is sufficient space for air to
circulate around the PC.

The second sounds suspiciously like the power supply.  Some printers
have a similar problem, a high pitched hum.