Make sure that you have running only one Anti-Virus in your machine. Running more than one Anti-Virus, may affect your machine.
You can go for Avast or Avg.
After scanning your system, try cleaning Malwares, adwares etc..
You can go for Malwarebytes, Remove it pro, Trojan remover, Hitman pro etc.. After Cleaning your system with tose applications, clean your system using CCleaner.