Help with Error message

[Lord_of_Hordes]

I recently purchased Overlord II through Steam. The game was playing really laggy, so I upgraded my graphics card to a Nvidia GeForce 9500 GT. When I started the game, I got a message saying that this was my first time logging in to Steam from this computer, and I had to get a confirmation code in an e-mail to continue (strange...but, ok). Did that, and when it started loading the game I got the error message listed in the title. The new graphics card installed fine and seems to be working fine, as I did a troubleshoot and the wizard told me the device was working properly with no conflicts. Also, I have other games (not through Steam) on my pc, and they work just fine, and look spectacular with my new graphics card. I thought that maybe Steam was configured to my old graphics card or something I was unaware of, so I uninstalled Steam (lost my game saves in the process, but oh well), then downloaded Steam again, and I am still getting the same error message: "Failed To Start Game (unkown error). I looked through the FAQs, and couldn't find anything that says anything about what I am experiencing. I checked to see if I had any conflicting Nvidia programs installed, but neither of the two Nvidia programs listed on the site are present on my computer. I also tried deleting the Appache folder from the Steam folder, and I still get the same error message. Also did the Verifying Steam cache files...no luck. I only have Windows Firewall and Microsoft Security Essentials, but they are both configured to allow Steam and Overlord II to have access. I can't think of any other information that you might need. So, if you need more information, please tell me what you need. If there is a specific action I need to take with my new graphics card, changing some settings or anything, please let me know what they need to be.

Specs:
Dell Inspiron 531 desktop
Windows XP service pack 3
148 GB hard drive (58 GB free space)
AMD Sempron Processor LE-1300 2.31 GHz
2.00 GB RAM
Nvidia GeForce 9500 GT graphics card

Keep in mind that the game was playing before I installed the new graphics card (on the lowest resolutions and graphics settings possible) but it was extremely slow and laggy. Steam can't start the game for some reason now. My other games I own that are fully installed on my PC work perfectly. I do have a new processor upgrade, but I haven't installed that yet. I would like to get the game running again to make sure everything is working properly before I do that.

It was suggested to me in the Help and Tips forum to try posting this here and I might get a response. Any help would be appreciated. :)

[Captain Havelock]

I'm haveing the same issues. somthing abount C++

[Arg81]

this is a known bug. It's to do with Nvidia Physix, even if you don't have a nVidia card... I used the guide here today, got it working for me http://robertmassaioli.wordpress.com/2012/01/14/fixing-the-physx-failed-to-install-error/

just re-download the version of Physix you have, uninstall it, reinstall it and Overlord 2 will start OK.

[Snootboop]

lualar it works!