How do i get rid of this

I somehow got something called antivirus soft installed on my computer and cant get it off. Tried using revo uninstaller but it wont let that open. also tried task manager but i wont let that open either. Please help me this is pissing me off telling me ever 2 seconds that something is infected.

Download OTL by OldTimer to your Desktop.

• Close all windows and double click OTL.exe
  
• Click Run Scan and let the program run uninterrupted
  
• It will produce two logs for you, one will pop up - OTL.txt, the other will be saved on your Desktop - Extras.txt. Post both logs in this thread.
  
• You may need to use two posts to get it all.