The idea is that even if you're using an administrative account, should a file try to execute and make system changes (such as a piece of malicious software trying to attack your PC after downloading from a malicious website) UAC will pop up and warn you about it, thus giving you the opportunity to deny the program system access, thus preventing the infection. It's basically a step by Microsoft to help mitigate the risks posed to users who always run their computers using an administrative user account, something that has proven to be quite risky given XP and previous OS's track records for contracting infections. They also cannot create/delete/modify most registry locations, again, preventing system changes. Basically UAC makes sure that every program that runs executes with the lowest level of privelages, meaning they can't do certain things such as create/delete/alter files in certain key locations such as the Windows system folder, the Program Files directory and other critical areas that make system wide changes. Have you ever heard of sandboxing applications such as sandboxie? It works sort of like that.

I uninstalled Malwarebytes, ran mbam-clean, and reinstalled it, and it's still behaving the same way. I ran the compatibility troubleshooter and was given the result that mbam was 'incompatible.' In fact, I even receive the prompt when opening the program using the 'Run as administrator' option from the context menu. I get the same result when setting the 'run as administrator' option under Compatibility mode. However, I still receive the UAC prompt when opening the program. (The user account I am using is designated as an administrator.) Clicking on the 'Continue' button is not followed by any other prompt, and the 'run as administrator' option remains checked. When I set my shortcuts to run the program as an administrator, I first receive an 'access denied' popup telling me that I must provide an administrator password to make the change. 1.42 on it, but I cannot get the program to run without receiving the UAC prompt asking if I want to allow the program to make changes to the computer. I recently purchased a new Sony Vaio laptop loaded with Windows 7 Home Premium 64 bit.

Malwarebytes windows xp mode windows 7