Go into safe mode onto you cpu. while your computer is starting press f8 and use arrow keys to select START SAFE MODE WITH NETWORKING
After that go into your control panel and find Uninstall/edit programs.
Find system care antivirus and uninstall it.
As soon as you are done go online and download a good antivirus and firwall. (I prefer Avast and malware bytes anti malware. Comodo is a good firewall too)
Install them and restart your cpu.
As soon as you restart on Avast and Malware bytes and start scanning your computer.
Always have your online security on when surfing! good luck! :)