You may wish to going back to a previous System Restore point if you have one. It will show the date. It won't remove any documents, but it will programs.
While you may have a virus, my advice is to do this:
1. Use System Restore and restore a point prior to your problem
2. then install and run Malwarebytes free version and Spybot Search and Destroy then scan your system for issues (S&D will find tracking bugs for your browsers which is normal)
3. Re-install any programs which System Restore may have removed if installed after the restore point.
4. If things work, create an IMAGE of your C-drive to a separate hard drive. I recommend Acronis True Image. There is a free version at Seagate and Western Digital if you have one if their drives (can be USB or internal).
Windows 7 has an Image tool but it's not as good. I bought the full version of Acronis TI and have an automated setup now.
FYI, its a good idea to periodically turn System Restore OFF then ON again if things are working. If a Restore point is too old it may be buggy itself if too many things have changed since then. I flush it every few months. This combined with my Acronis backups have led to a period of two years in which I didn't need to reinstall Windows!