"Run a DLL as an App"

Someone might have a more specific idea for you, but I suggest that you download SuperAntiSpyware (free version) from www.superantispyware.com and update it and perform a full system scan. Allow it to remove any infections that it finds. Then comes the good part. SuperAntiSpyware includes some fixes for things that spyware disables like System Restore. You should run the fix for System Restore and see if that fixes your problem. If not, we will try another solution. Here are the directions to run the fix:

Start SuperAntiSpyware
Click on the Preferences Button
Click on the Repairs Tab
Scroll down until you see "Repair broken Windows System Restore Service. highlight it and then click the Perform Repair Button
Close SuperAntiSpyware
Restart your System
Try performing a System Restore

Cheers!