If I understand what you are asking what you want to do is simply change you drive letters.  With XP go into the control panel, administrative tools, then computer management.  On the right side will be a listing of storage and under that is disk management.  When you click on disk management it will show all of your drives on the right hand side of the screen.  Right clink on your desired drive and choose change drive letter and path.  It will let you reletter your drives.  You may have to rename a couple times to get your desired end result because you can't rename you HDD C until you rename the other one the is currently C:  The one problem this may create is broken links as programs look for files on F when they are now on C.  Most windows things should work fine, the problems will be things like shortcuts in Office.  I know that one from experience but it only takes a little use to get all of them updated.

Gunner