If you want to know the drive letter of where YOUR application has started from the use this code:
Dim ProgDrive as string
Dim ProgPath as string
ProgPath = App.Path
ProgDrive = Left$(ProgPath,1)
OR
ProgDrive = Left$(App.Path,1)
The built in procedure App.Path will always supply the full path to where your application is started from. With this information, pulling the first character form the returned string (using Left or Left$) will give us the drive letter.
Hope this helps...
===========================
Life is like a box of BASIC