Disable User Account Control(UAC) For Administrators Only

If you can’t stand the User Account Control prompts, but you’d still like to retain a little bit of security, you can disable it for Administrator accounts only. What we’ll be doing is actually changing Windows Vista to automatically elevate the privilege level for administrators without prompting.
Note: Disabling UAC will lead to a less secure system, so be warned.
The nice thing about doing it this way is that regular users as well as Internet Explorer still run as regular users, and would still use the normal security mechanisms.
Disable on Windows 7 or Vista Business or Ultimate
To configure this setting on Windows 7 / Vista Business and Ultimate, you can use the Local Security Policy configuration. Just type in secpol.msc into the Start menu search box and hit enter.
Now browse down to Local Policies \ Security Options

Find the following in the list: “User Account Control: Behavior of the elevation prompt for administrators in Admin Approval Mode” and double-click on it.

Change the setting to “Elevate without prompting”. You should be all done.
Disable for Windows 7 or Vista Home
For Windows Vista Home users, the Local Security Policy doesn’t come with the distribution, so you’ll have to use the following registry file.
Just download, extract and double-click on the registry hack file to add the information into the registry. That’s all there is to it. Update: I’ve added in another registry hack file to re-enable UAC again.