How do I get rid of this fake "System tools" virus?

Reboot PC and press the F8 key a couple of times before the Windows screen appears. Enter Safe Mode, or Safe Mode with Networking if you need network access) and download MalwareBytes from google ,Install it, update, and run a full system scan. Remove everything it finds. Next, run a full antivirus scan with something like Microsoft Security Essentials .Auslogics disk defrag and Auslogics registry cleaner are very good and fast to keep you clean and running good .all are free ,just google them