Green AV Remove

It may be possible to terminate the running processes from green AV while you are logged onto windows normally, but you may need to reboot into safe mode. gav.exe, gra.exe and greenav2009.exe are the filenames that have thus far been reported as used by Green Antivirus.

After booting into safe mode delete or rename C:\Program Files\Documents and Settings\All Users\Application Data\GAV\gav.exe since that's the main program executable.
Look for mgrdll.exe and delete it and also take out the \Application Data\GAV folder.

From what I see, for some users they may find GRA instead of GAV for the filename.

Green antivirus 2009 may also go under the name greenav2009.exe in the process manager. Look for anything similar or related to this name if you can't find one of the items specifically mentioned.

Also if it is named differently than above look to delete or rename the files that you find acting as green av to successfully remove it.

After you have a "foothold" of sorts and have made some progress against a pest like this continue to make sure you get respected malware removal like malware bytes antimalware, sypbot, AVG, etc. on the system and update them, run full scans and test with a few reboots to make sure the baddie doesn't resurface. (See my Virus removal toolkit for download links.)