Hard Disk not recognised by Desk top

[suave]

This is a sticky problem. Got a Hard disk from Magnetic Data Technolies ATA 133, 7200 rpm and 40 GB Hard Disk. When the computer was booted up, the BIOS recognises the existence of the Hard Disk and it shows up on the Device Manager. But when you try view the drive under My Computer, there was no logical assignment of the drive. You could not find it under directory and you cannot re-format it.

[squirrel]

1) Specs for the PC?

2) Did it ever work properly? (if not, is it still under warantee?)

3) Is there anything essential on there (i.e. important documents or files)?

4) Any other details?