Regedit.....
yeah it's possible.
Just type regedit in the run box of windows
Hit Ctrl F
have the "keys" checked and the "Match whole string only" checked
do a search for: Square Soft Inc.
It should find the Final Fantasy 7 registery, if it doesn't, hit F3 until it does.
Click/Highlight the "Final Fantasy VII" text
Look for the string that says MoviePath (it should be the last one)
That's where you tell FF7 where the movies are at. Just double click on MoviePath to change the value.
Now, you probably already know about that, being it the same as mentioned earlier by "nayoung". You probably miss-typed the path.