I suggest you download CCleaner (get the Slim version
here) and run it's Windows scan and it's Registry scan. Take some time to look at the options for the Windows scan; you may want to un-select certain items but, of course, if you un-select too much, you'll be negating the purpose of the scan.
When you run the registry scan, you will be prompted to backup the registry. Do so, and then have CCleaner fix all registry issues found. Repeat the registry scan; sometimes, additional items will be found upon repeat scans.
This may not solve the problem, but it's still a good thing to do. If this does not help, you may have malware issues, and some of our malware experts here can help with that.
