To put it simply, I noticed UAC was disabled so I enabled it. I was prompted to reboot the computer for the changes to take effect. Upon my reboot I checked the settings again as I hadn't disabled UAC in the first place. It was again set to off (never notify). For the heck of it I repeated the process a couple of more times. Same result each time.
I have Microsoft Security Essentials running a full scan nightly so I should be protected from viruses. I also did an on demand scan with the online tool at www.antivirus.com. Nothing was found.
Other than the fact that UAC is being disabled on each reboot I have no other reason to suspect a virus.
So my question is does anyone have insight into if this is a possible problem with a virus or other malware changing my UAC settings on each boot or is it possibly a problem with Windows and UAC itself? If it is malware are there suggestions for other products outside of the ones I have used to detect and remove it.