|Download MalwareBytes freebie and run it. If it won't run you can change the exe file to either cmd or bat (that applies to both the download and the program exe).|
If necessary download it to a flash drive on another computer then transfer it across.
Why on earth have you no Antivirus when there are perfectly good free ones about? Some examples:
Microsoft Security Essentials
Please come back and let us know how you got on.