I have the free version. Open the program and select "scan". Then choose "custom scan". Make sure all 4 check boxes are checked (typically the rootkit one is not checked, make sure to check it). Both drop boxes should be set to "treat detections as malware". Select the drive or drives you want scanned. Press "start scan". This will take time and require a reboot. As it reboots, it will scan the boot drive. Hopefully, it will find the evil little bugger torturing you. I have had good luck with Malwarebytes. I also use Avast for free anti-virus. It seems to do a good job.