Zombie Driver HD
From: http://forums.steampowered.com/forums/showthread.php?t=1655363&page=3
There is a problem with the PhysX driver in your system. Could you please try to manually reinstall PhysX using the package that is provided with Zombie Driver? You will have to first uninstall the PhysX driver in your system [for Windows 7: Control Panel/Programs and Features] and after that install the one that comes with Zombie Driver.
You can find it in this directory: \Steam\SteamApps\common\zombie driver\PhysX\PhysX_9.09.0814_SystemSoftware.exe
There was a bug in one of the Nvidia PhysX installers that corrupted the drivers that are needed for Zombie Driver. This procedure should fix your problem.
Thank you for your patience. Zombie Driver Support Team
[11-02-2011, 07:38 AM]
[Ferdyzor - EXOR Studios]