If you are using Windows 7 you should have noticed the (annoying) UAC security feature. If you want to completely remove user account control in windows 7, the best way to make a small change in registry.
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System] "EnableLUA"=dword:00000000
that’s it!
p.s I haven’t tried this in Win8, but I think it should work.