go to start and in the search box type " GPEDIT.MSC"
from there, in "Computer configuration, go to -->windows settings-->security settings --> local policies -->security options.
Scroll down until you see :
UAC : Behaviour of the elevation prompt for Administrators in Admini approval mode.
disable it, then disable this one too :
UAC : Behavior of the elevation prompt for standard users.
or better yet go to start-->start search-->msconfig
on the Tools tab. Scroll down and locate "Disable UAC" Click on "launch"
This is how i did mine, there are tweaks and programs of google like
THIS page, or google "Disable Vista UAC"