|try tapping f8 and select safe mode with networking. See if you can access the start menu in there.|
While in safe mode, download and run these in the exact order:
1- rkill.exe (will stop the malware process)
2- tdss killer ( will remove the unwanted rootkit if there)
3- malwarebytes (run a full scan and fix all it finds)
Then reboot your PC and try it again.
Some HELP in posting on Computing.net plus free progs and instructions Cheers