Hi all -  
 
  I build a (mostly) new system - A64 3200/ASUS K8N/1gbDDR/x1950xt - and I had a problem installing Windows, so I started over again, but now my computer isn't recognizing my onboard network card.  With this new box I installed WinXP Pro 64-bit, it ran great for a couple months, then I decided I didn't like 64-bit Windows, so I formatted and went back to Win XP Pro (32-bit).  This is where the install went south, so I aborted, formatted, and tried again.  
 
  But two major problems cropped up - first, the computer stopped recognizing my onboard network card - it's been performing fine for two months, so I don't know why.  Installed and reinstalled all drivers, no change.  Also, the hard drive started reading as 136gb.  It reads as 136GB during Windows install, and I took it out and plugged it into another box that's running WinXP Pro SP2, still same 136GB.
 
  Anyone know why either one of these issues is happening?
 
Thanks

Try running the diagnostic/repair software from the hdd mfg from a floppy

first how big is the original hdd? 2nd what version was the win XP32bit when you installed?  
If it was pre SP1 (2002 edition or around that era) then the largest size it can make a hdd is around 136Gb, I know since it decided to wipe my 300 and change it down the 136 with all my data still on it.  
Anyway back to the problem at hand. Go to Control panel/advanced View/Admin tools/Computer management, then select storage, If you've got SP2 or SP1 installed then it should show the rest of the hdd as unformatted, To access it you can create a new patition and use it as a 2nd hdd, or (though i dont know if windows management supports this, you might have to go 3rd party and get a tool like patition magic) extend your original patition to encompass the who hard drive.  
As to the onboard network card, check the BIOS settings, make sure its not disabled. If it still doesnt show up under network devices then i'm guessing that its either broke (happened to a mate of mine) or you havent installed the drivers, though after ^dating to SP2, it shouldnt really matter.

If your hard drive appears on WinXP SP2 as 136Gb, that's strange..  try reinstalling support pack 2.