Both drives have XP installed and both drives have "C" drives...

Had you installed XP on the second drive when both drives were hooked up - the second install would have taken a different drive letter. AND, the second XP install would have created a Dual Boot menu.

So, if you get one drive to see the other drive you run the risk of XP renaming the drive letter of the other install and effectily killing it since it has tons of registry entries that won't change.