1. Install Malware bytes and AVG-free make sure they are updated. 
2. Boot into safe mode (F8 during boot up)
3. Run full system scans with AVG and Malwarebyts  until it comes up clean. 
4. Reboot into normal mode
5. Run a full system scan with both again to make sure that they are gone.
6. If the pc is running xp I would look into installing spybot to keep my registry safe from more bugs coming in. Or I would pay Open22 $25 to do it for me