Second HDD not showing in My Computer but showing in BIOS

[thomas6979]

Hello, my 2nd hard disk with os win xp not showing in my computer page.In the disk management page sata hard disk(system)(ntfs)with os win xp shows online and the 2nd hard disk(active)(fat32)also shows online

 

[house70]

Is this HDD the one with the OS on it?
Which HDD shows up in my Computer? the one with the OS, or the other one?

 

[WyomingKnott]

From what you posted, this drive already has a filesystem on it. Could you
1) Open Disk Management again, just right-click on the fat32 filesystem and try to Assign a Disk Letter?
2) If that doesn't work, try checking the filesystem to see if it is corrupted.