Comodo Antivirus Locked up my computer

I’ve winXP home edition.
After installing free “Comodo” “anti” VIRUS program yesterday it locked up my laptop and after having to force the computer to shut down by pressing the OFF buttom for awhile, it couldn’t startup again.
The computer was even unable to read from CD drive…!!
The only way to revive my laptop computer was by disconnecting (removing) the battery and the power cable.
Then I could start up in Safe Mode and obviously sent “Comodo” down the drain.
This was a terrible experience, I will never install any “Comodo” application again!