Shows the variations of your problem.
To remove the infection run these in the exact order
1- rkill.exe (will kill the malware process)
2- tdss killer (will remove the hidden rootkit if found)
run a full scan and fix all it finds
Reboot your PC and see if the problem persists.
Now download Ccleaner Slim
Run the cleaner deleting all it finds, then click on the registry icon on the left of it and delete everything it finds.
That is an extremely safe cleaner and i would not suggest using the norton registry cleaner, you may delete something vital to your PC .
Some HELP in posting on Computing.net plus free progs and instructions Cheers