My computer started running very slow today. I've done a couple restores to earlier restore points which haven't helped. The performance trouble shooter won't work and I am trying to do a scan with Microsoft Security Essentials but it is just creeping along. I tried to do an elevated command prompt as Administrator so I could try SFC/Scannow but I get a message that says "Do you want to alow the following program from an unknown publisher to make changes...." I got a similar message which concerned c/windows/system 32/rstrui.exe which I had to allow inorder to get my restore points to be accessible. Any ideas?