Can't restart both computers after installing V2

I uploaded the new Firewall today to three computers both running Windows XP. On two computers I set it to custom and on one I used advanced. The advanced settings loaded perfectly but both of the other computers no will not boot. I get a blue screen saying there is a conflict with the new software. I also cannot boot either computer in safe mode to instigate a system restore so I have two dead computers. Thanks Comodo!

I have called an engineer who can’t come until next week but wonder if anyone has any suggestions in the meantime?