First try updating all your drivers. Especially the display ones. Then I would try running some good deep scans for both viruses and malware. Most programs don't check for both. If neither of these resolves it or turns up any problems, then I would look at the last thing that was done before this started happening. Program install, update, what? Then go to "Start" and in the search box type "system restore" (without the quotes). Choose "System Restore" from the list (it should be at the top) and locate a restore point that is prior to the problem starting. Choose that point and start the restoration.
NOTE: This will not delete any files you have on the computer, it will, however, remove anything that was installed after that restore...