Hard Drive Gets Repartitioned??

[m3zzr]

A friend of mine recently asked me to look at his computer, as one of his hard drives started to show as 40GB and unformated, even tho it was a 300GB. (within windows)

Upon closer inspection, and the same thing happening to other hard drives in his system, it appears that after some restarts, any one hard drive in the system becomes re-partitions as 40GB unformated and the rest of the hard drive unallocated.. this is not just happening to the internal ATA/SATA drives but to USB hard drives which are plugged in as well.

Does anyone have any ideas what could cause this.

 

[m3zzr]

It's running an Athlon 64 3.something, so it should be fine

 

[m3zzr]

Athlon 64 3.4Ghz
1GB RAM
Windows XP SP2 (all latest updates)

Internal
1x Maxtor 40GB (windows installation, NTFS)
1x Maxtor SATA 160GB (NTFS)
1x Maxtor SATA 300GB (NTFS)

External

3x 300GB USB2 Maxtor Hard Drive

In Disk management they all show as partitioned and healthy, until a restart, in which case... it will randomly choose an hard drive, and it shows one as being partitioned 40GB primary unformatted and the rest of the hard drive as unallocated..

I have done the usual reformat, checked all cables etc... checked all motherboard settings etc