If a user wishes to install a new program they are presented with the option either to allow the installer complete system privileges or not to run the program at all.

Rutkowska wrote on her Invisible Things blog: "That means that if you downloaded some freeware Tetris game, you will have to run its installer as administrator, giving it full access to all your file system and registry, and allowing it to load kernel drivers! Why should a Tetris installer be allowed to load kernel drivers?

"I would like to be offered a choice whether to fully trust a given installer executable (and run it as full administrator) or just allow it to add a folder in C:\Program Files and some keys under HKLM\Software and do nothing more.

"I could do that under Windows XP, but apparently I can't under Vista, which is a bit disturbing."