Not partitions, hard drives? I wanted to reformat my PC but they're broken up into two 40 Gig hard drives, is there anyway to combine both drives so I could install Windows XP on one drive?

On the one hand you say this isn't partitions and yet the rest of your post refers to partitions.
Now, please clarify, are these two physically different drives or two parts of the same drive?

Two different physical drives, sorry.

No, they are attached on the PC by a cable as different connections, therefore they would be given 2 drives letters

- Usually C: and D:

So you will just have C and D and then your CD drive letter names