did you make any changes in the registry at all?. If you used regedit you just need to go back in and set the default again BUT DO NOT RESET THE COMPLETE REGISTRY!.
If you wait a while, maybe someone else can help you further, all I have is for you to do a full system reset which will reset your entire PC!.
Generally speaking a System Restore to a restore point prior to the date of the problem will often reset the registry to that date.
Certainly worth a try.
Want to reply to this thread or ask your own question?
You'll need to choose a username for the site, which only take a couple of moments. After that, you can post your question and our members will help you out.