MAMEWorld Forums - News - Re: Compiling page updated

No, there's actually a sensible reason for it. Microsoft's goal with UAC was to finally break the vicious circle of "Everyone runs Windows with Administrator privileges because there are so many applications that require it, usually for stupid reasons like putting config files or user data into C:\Program Files; and because everyone does run as Administrator, there's no incentive for application vendors to fix their applications".

There are two possible reasons an application might want to write into C:\Program Files (or another protected folder):

1) It's an old Win9x-vintage application, or one whose author never got the memo about Windows becoming a multiuser OS where you can't just write files wherever you want. In this case, UAC silently redirects the write to a "virtual" copy of the protected folder under the current user's home folder. This way, users can run their old and broken apps without ever seeing a UAC prompt and without any chance that the broken app can trash system files.

2) It's an application installer or updater, in which case it really does need to write to the actual C:\Program Files folder, not to a virtual copy of it, and therefore UAC really does have to prompt the user for an Administrator password.

Microsoft needed a way to distinguish between 1) and 2) that was compatible with old applications and that didn't require user intervention. The method they chose was a heuristic that is described here under "Installer Detection". Short version: any executable whose metadata contains certain strings associated with installers or updaters (such as "InstallShield") or whose filename implies that it's an installer or updater is treated as 2), meaning you get a UAC prompt when you try to run it.

Edited by AWJ (09/11/12 09:40 AM)