multiple file copy causes drive to go unrecognized

[brookefox]

My two laptop hard drives decided to go south at the same time a few weeks ago. The boot drive has disappeared completely and been removed but the second one, which had a mirror of the system and program files of the first and does still boot, comes in and out of recognition. If I try to backup certain music files from it, files which otherwise seem OK, the backup fails as the source drive disappears until the next reboot. Chkdsk had been run to 'fix,' before that I could not clone the system and program files on the new (refurb) identical replacement. Any suggestion on keeping the drive recognized so I can get the data backed up?

Windows Vista
two installed now drives identical: the failing one (source) and the replacement (destination):
Seagate MOMENTUS drive - 7200-RPM SATA - 750 GB
model no.: ST9750420AS

 

[MilesAhead]

"Can you put the drive that works sometimes in another machine? It sounds to me like the disk controller might be crapping out.

 

[brookefox]

Well, thanks. I'll keep that in mind for once I ditch the bad one. Right now as I'm trying to copy from it to the other and doing it in the same machine is easier, if possible, that is.