I have a problem similar to alot of posts dealing with the system restore. Also my C drive doesnt show up on my device manager and a whole host of other odd symptoms that I cant think of offhand.
It started with a system scan done by some sort of antivirus that I dont even remember downloading. It said I had a bunch of viruses and etc and needed to purchase to fix the pblms. I didnt purchase and it has led to these problems. I have tried a bunch of different things that have seemed to slow down the problems but not completely fix whatever is wrong. I have given up on trying to fix it myself since i really dont know what i am doing and my "IT" department has no clue and no motivation to look further into it. They just want me to use a different computer (easy fix for them and days of downloading programs and files and etc. to make the new computer able to do what my computer now can do). I would really appreciate help on this one. Let me know if you need me to run something and send an output file or whatever else may be needed to diagnose/fix this problem. Thanks in advance.
Your PC sound like it has been infected with rogue anti virus. This variant of threat is not easy to remove and you can on how to remove a rogue antivirus from here http://thecooltools.blogspot.com/2009/06/remove-windefender-2009-how-to.html