Do you have a Vista password? FAH needs one.I read what the thread said but I tried all those already. I had UAC disabled for a long time already and i did all the compatibility things. I also dont have the FAH folder in Program Files. Its in an external drive.
Did you select "Run as administrator" for both the install.bat file and the FAH installer?
Did you change the properties of FAH to "Run as Administrator"? You will need to create a shortcut for that.