I'm in sort of a predicament here...

I just purchased a Seagate 400GB PATA HD over the weekend, and I took
it home to replace the failed hard drive in my former Maxtor External
250GB FW/USB2 enclosure.

I removed the dead drive from the enclosure and placed the new 400GB
drive inside, connected it, plugged it into a firewire port and
powered it on....

My WS2003 SP1 PC (MSDN) only recognized 128GB (no partitions yet, just
128GB unallocated space)... Keep in mind, I just removed a 250GB drive
from the same enclosure, so the 137GB limit was not the problem. So I
took the drive out and decided to try the drive in my new Dell 8400
PC. Still showed 128GB total unallocated space.

So I returned the drive for an identical one. I had the techs at the
store format it with one 400GB NTFS partition. Worked fine in the
store (I watched them). They had it plugged into an Adaptec USB2.0
enclosure. So I bought one of those, too.

I took the formatted drive and the enclosure home, and since the drive
was already formatted, I decided to give it one final go in the Maxtor
enclosure...

Upon powering up the drive in the Maxtor enclosure, I once again saw
128GB of unallocated space. At this point I junked the Maxtor
enclosure, and placed the drive into the new Adaptec enclosure. Still
shows 128GB of unallocated space. Is it possible that the Maxtor
enclosure writes something to the HD itself?

I'm not as familiar with hardware as I am with software. Is this
something that erasing the MBR might fix? I don't want to return it
again.

Thanks...

Have you gone through the trouble shooting steps at
http://www.seagate.com/support/kb/disc/capacity/137/index.html ?

Yes. And as I said, it only did this after I plugged it into the
Maxtor enclosure. Before I put it into that enclosure, it shows 400
gigs of empty space. After that it doesn't recognize more than 128GB
anywhere I put it. It's really strange.

I recently had the same problem with a Hitachi drive in the same type
of Maxtor enclosure - it turns out that the drive's reported LBA size
got changed to 128GB - I haven't figured out why it changed yet - but
that is what happened to cause it.

The solution was to get a utility from the drive manufacturer to let
me change the reported LBA size back to the native LBA size.

According to Seagate, the procedure for doing this with their drives is:

"- Load DiscWizard Starter Edition
- Select "Utilities"
- Select "Set Hard Drive Size"
- Select the correct drive ( if more than one drive installed)
- If the "Current Maximum LBA/CYL" is not equal to the "Native Maximum
LBA/CYL" values, change it to the value in the Native Maximum LBA/CYL
number. This should force the drive to report the correct size to the BIOS.

If you are still unable to read the full capacity of the drive, use
DiscWizard Starter Edition to run a Zero Fill on the drive. This will
write through the MBR with zero's to remove any remnants of the DDO."

Hopefully that will get it sorted for you. I haven't figured out if
the same thing will happen again with the Maxtor enclosure, or if it's
because of what I connected it to afterwards - I'm about to find out.

Best wishes from sunny London!

Andrew.

London --SUNNY?  Hmmmmm....

Same Problem here.
I put a 250GB HDD from Western Digital in a Maxtor PS 5000 external
case. The max. size is 128GB...
The HDD was in before was 200gb so it shouldn't be an OS problem. But
anyway I use WinXP SP2
Regards
Nicolaj

goto bios
if the bios can't recognize the right capcitance, update the bios

if not solved

update to windows 2000 sp3 or windows sp1
download and intall MAXTOR BIG DRIVE ENABLER from 

http://www.maxtor.com/portal/site/Maxtor/menuitem.3c67e325e0a6b1f6294198b091346068/?channelpath=%2Fen_us%2FSupport%2FSoftware%20Downloads%2FATA%20Hard%20Drives&downloadID=11

if not solved 

install INTEL application accelaerator(IAA) only support 810, 810E,
810E2, 810L, 815, 815EP, 815G, 815EG, 815P, 820, 820E, 840, 845, 845E,
845G, 845GE, 845GL, 845GV, 845PE, 850, 850E, 860

if not work
try another brand of enclsure

Good luck
Regards
Aeolus

try this out maybe helpful
http://www.seagate.com/support/disc/download/reg_48bit_lba.exe