Thanks 0x517A5D, that worked. A daisy chain of hidden files I wouldn't have thought of there. Yes, I put DF in my prog files, trying to keep my machine neat and tidy as to where everything is, program files, not in several different folders. I realize the error in that with vista now. New question, if I simply moved DF to a folder not in prog files, will it break everything?
No, it won't break. But you have to move both sets of directories, and do it in the right order, Program Files first, then everything in the VirtualStore. Since you're worried, I suggest copying the files instead of moving.
So for instance, go to Start/Computer, choose the C: drive, make a new folder in it named Games. Then open the new Games folder. Leave it open.
Go to Start/Computer, choose C:, choose Program files. Find the Dwarf Fortress folder in the list. Right-click it, choose "Copy".
Switch windows back to the open Games folder, right-click a white area (empty space), choose Paste.
Leave Games open. Go to "C:\Users\
your user name\AppData\Local\VirtualStore\Program Files\". Find the Dwarf Fortress folder in the list. Right-click it, choose "Copy".
Switch windows back to the open Games folder, right-click a white area (empty space), choose Paste.
It will complain that it may replace existing files.
This is OK. Choose Yes to All.
Then all you need to do is change your shortcuts, if you use them. Once you've verified that the game works in the new location, delete the old Program Files Dwarf Fortress and the VirtualStore one. Delete them to the trash instead of a shift-delete, just in case.