All of our users are not local admins, so when they need to install something, it prompts for the domain admin credentials. I was doing an update on someone's PC yesterday and it doesn't prompt for the admin credentials and tries to start the install, which fails because they don't have the permissions to install. When I try to launch the UAC settings, the window just flashes and doesn't actually open for me to see when it's supposed to prompt. I've tested this on another machine and a simple user can open the UAC settings. I saw somewhere to run the sfc /scannow command but that didn't resolve the issue. Any other ideas?