Anything With The Blue Administrator Shield Doesn't Work

trying to access my Network sharing properties and it said an unexpected error occurred. I did an SFC Scan and it says windows have found corrupted files but cant repair them.i did a virus check but no virus. When i try to change UAC settings it has this error - Bad Image C:windowssystem32comsvcs.dll is either not designed to run on Windows or it contains an error.So basically if it has the blue and yellow shield i can't access it such as: Network properties, Add or Change user account, Change UAC, Parental controls and whatever else.All im trying to do is access the Network Sharing properties so i can hook up my Xbox 360 directly to my laptop and use it as a router.I'm trying to avoid reformatting my computer because i have too much stuff and no where to put it.::I just tried using the other administrator account that i already had but that doesnt work either. Same things go on in that one. Also, if it doesn't give me an error message when i try to click on something with the shield, it just wont do anything, nothing happens.::::Just checked to see if it really was ALL the items with a blue and yellow shield. It's not. There are a few that work like device manager. But the ones i need still dont work.