Disabling UAC (User Account Control) for Vista and Windows 7
Vista

Go to Start>Control Panel and type "uac" into the search bar. Click on the "Turn User Account Control (UAC) on or off" link.

In the next window, uncheck the box by "Use User Account Control (UAC) to help protect your computer" and click OK. Restart your computer for the changes to take effect.
Windows 7

Go to the Start bar and type "uac" into the search bar. Click on the "Change User Account Control Settings" link.

In the next window, drag the slider down to the bottom to completely disable the UAC. Click OK and restart your computer for the changes to take effect.