|Try booting in Safe Mode with Networking (F8 at start up and select from list) and try a System Restore from there to a date well before you had the problem. It could be something you did (but I cannot think of what) but it could also be malware of some type so whether it works or not, install, update, and run Malwarebytes. Then update and run your antivirus program. Try System Restore again if it did not work the first time and if it works now, run Malwarebytes again.|
If System Restore does not work from there at all, you can run it from a Windows 7 Repair Disk. If you have not made one yet, you can make one from another Windows 7 machine as long as both are either 32bit or 64bit and use that. Since you boot to the repair disk, you are using the restore program on the repair disk and your restore points that are on your hard drive so this should work and fix system files and registry errors and get you going again.
You have to be a little bit crazy to keep you from going insane.