In windows 7 UAC or User Account Control is much better than it was in Vista. You can control how intrusive UAC is or you can completely turn it off. To find how to start first open the Control Panel by clicking start Control Panel. When control panel opens click User Accounts.
Once User accounts open click on Change User Account Control Settings.
Once you click that, the last window opens with a slider where you can control UAC. By default it is set to the second notch down that dims the desktop when it asks if you want to allow something to run. Personally I find this very annoying and I have moved it down one notch where it still asks when installing programs but does not dim desktop. You can also turn it all the way down and off but I would not recommend that.
