Find your PST file - do a search (include hidden/system folders as well) on
the other drive.
You don't mention your OS, but if your current login has administrator
rights on the computer, do a search for *.pst (make sure to search
hidden/system folders as well). If you can't find anything, you may need to
take ownership of the folder & all subfolders - see
http://support.microsoft.com/default.aspx?scid=kb;en-us;268019 for help
(written for W2k but should be the same for XP) and try the search again.
When you find the PST file, you can move it to the location of your choice -
rename it yourname.pst so you'll know what it is. You can also delete the
new outlook.pst file you'll find in your own profile directory while Outlook
is closed....then open Outlook and when it complains it can't find the file,
direct it to the yourname.pst file.
Note - I'd redirect My Documents on the desktop to something you set up
yourself, such as c:\data (choose 'move'), and put the PST file in
c:\data\outlook - I don't like using the default profile folders as you may
have problems with them if your profile gets hosed. Hope this helps.