Disabling UAC (User Account Control) in Microsoft Windows Vista

Note: Disabling UAC will lead to a less secure system, so be warned.
Open up Control Panel, and type in "UAC" into the search box. You'll see a link for "Turn User Account Control (UAC) on or off":
On the next screen you should uncheck the box for "Use User Account Control (UAC)", and then click on the OK button.
You'll need to reboot your computer before the changes take effect, but you should be all done with annoying prompts.