» Mon May 14, 2012 11:09 pm
If that issues is caused by UAC, you can either shut down UAC (don't remember how that's done, but google should give that answer, still, UAC is pretty useful so you shouldn't do that) or just reinstall the game outside of Program files folder. You'd have to reinstall Steam to do that, though.
But before doing something drastic, did the mod have files ending with .esm or .esp? only those appear and need to be checked in the Data Files.