I run Windows 7 64bit on a I5-750cpu. I installed the firewall Sept 2010 and it worked fine. Since then I have tried installing the update iin March and the latest update in June 2011 with the same results. The system seems to loop at a ceratin point(?) aand to get Windows back up, I hade to go into safe mode and disable all of Comodo's options, then reboot normally and uninstall Comodo, reboot and go back to the Sep download. I tried a complete resinstall instead of update which appeared OK but this morning after a Windows update, same thing. When it works, I like it, but spending 1-2 hours recovering isn't worth it so I switched to McAfee, free from AT&T. for now.