Windows 7 have an in-built protection of the program files directory, which makes changing files quite hard and annoying. This is good in the case that some unwanted program wants to access program files, so that is why UAC should not be disabled. Instead, like have been said, it is better to create a new directory (i call mine "games") where to install your games, specially those which you plan to tweak any files (even configuration files or the like). If you run Windows XP this does not apply, and i fail to see how it is sloppy file management to install games you plan to mod on program files.