|Go to Device Manager and see if there are any errors showing (usually yellow question marks). Quick route to Device Manger - type devmgmt.msc in the Run box and hit Enter key.|
Have you done anything to Display drivers lately, or did this suddenly just happen?
I doubt it's a virus, the symptoms are usually much more severe than that.
Re your post #3. When you say it didn't work, did it allow you to change the settings, or did you change them and it made no difference. What settings did you try to change?
We need more info because when working from afar we cannot see what you are seeing.
How to know you are getting old 1:
If you can remember when radishes tasted of something