If system restore doesn't help, download Malwarebytes:http://www.malwarebytes.org/mbam.php
Important: Rename the downloaded mbam-setup.exe file to something else, to help work
around certain malware that will block it from being run.
Does NOT need to be run in safe mode, it is designed to work best in normal mode.
Choose: 'Perform full scan'.
Sounds like malware, you may have to post in the 'Security, Am I Infected, What do I do', forum.
Avoid registry cleaners, boosters, etc, they may cause rather than solve problems.