I have a Malware Defense infection on my Windows XP Home computer. I am trying to install Malwarebytes to disinfect. I am also trying to download and install AVG Anti-Virus. In both cases the virus simply will not let me run these programs. I was finally able to get Process Explorer installed and running, but evidently the virus is hiding itself under a legitimate name or service. How does a virus block programs from running? I remember something about killbits. Is that how they block programs? or do they do so some other way? if I cannot stop the virus, how do I unblock the legitimate anti-virus programs in order to scan and disinfect? I am working remotely too, so I cannot separately disinfect the drive from another drive, which would probably work. Any ideas? perhaps there is a particular legitimate anit-malware program which cannot be blocked by rogue anti-malware?