64 bit W7 system here. I decided to try Pf (had it on an XP machine for a few years) but the installation resulted in W7s version of the bsod. Did I have to turn W7s firewall off prior to installation? I'd assumed the install wizard would do that. All I know is when I booted to finish the installation Windows hung and there wasn't anything being written to my SSD. Pretty nice how after I forced another shutdown and booted again, W7 offered automatic restore.