Something you ran under windows has gone and set the "host protected area" feature of the drive, hiding most of its capacity.

The drive itself is fine, and can be restored with a quick tweak.

If you can attach it directly (not USB) to a working Linux box (or the latest Ubuntu LiveCD), then get the latest version of the (my) hdparm utility from sourceforge (Ubuntu-8.04 has it installed by default), and use the -N flag to restore the drive to full capacity.

Something like this:

hdparm -N /dev/sdb
/dev/sdb:
max sectors = 65134/1953525168, HPA is enabled

hdparm -Np1953525168 /dev/sdb
/dev/sdb:
max sectors = 1953525168/1953525168, HPA is disabled