-computers may say you are not an administrator
-this is likely your security software stopping you, thinking you’re a virus or spyware
-could also be a simple bug in windows or security software
-turn off security software (just for a moment) and try again.
-turn off computer, boot into Safe Mode by tapping F8, go ‘start’, ‘run’, type ‘msconfig’ and try
turning off unwanted services again
-Try Autoruns http://www.microsoft.com/technet/sysinternals/Utilities/AutoRuns.mspx
-The problem could also be spyware of virus related. Malicious programs can cause weird things like this to happen. Update and run your ant-spyware or anti-virus to remove and detect and hopefully resolve the issue.