What is UAC?
Definition: User Access Control.
"UAC is not acceptable for me. Without any questions. That is MY computer, I am the owner – not Microsoft."
While this statement is certainly true at least for awhile, once malware installs, the computer belongs to the owner of the malware that gets installed because the computer owner had UAC turned off.
When folks complained that Microsoft didn't provide security in Windows, MS then implemented a great security feature in Vista and modified it somewhat in Windows 7. This feature allows nothing to be run or installed without the user saying 'it's OK.
But then Vista folks complained 'it's too much in my face' and promptly turned it off. (It was an all or nothing feature in Vista.) So much for more security for those folks.
Windows 7 users have options to modify UAC. To understand the options available in Windows 7, open Help and Support and type UAC in the search. There are a lot of entries here, but what you need to know is located in the 'What are User Account Control settings?'.
Screenshot of my settings for UAC