|I'm sorry, but I think you are infected.
1. Make backup of your registry.
2. Set a Restore Point, to prevent trouble if you make a mistake.
3. Remove sp.dll from Windows startup using antivirus (also check How To Remove section)Startup Optimizer.
4. Reboot your computer.
After reboot, execute this command:
regedit -s c:\windows\sp.dll
Delete Files on your hard drive (search from Widnows or System32 folder):
If you are not sure, use Ask Computer Gays service: