I just did a fresh install of Windows 7 RTM last night and tonight after getting COD:UO reinstalled and patched I fired it up and was greeted with the following.
Now I have been running COD:UO on Windows 7 on and off since the BETA and haven’t had too many issues with it except for PunkBuster. I didn’t really feel like messing with it at that point so I rebooted and logged back into my Windows XP account and fired up COD:UO. To my surprise I got the same exact error. After a few minutes of thinking and a bit of searching it came down to an upgraded graphics card driver because I had also just purchased a new EVGA GTX260 SSC Edition and installed the latest drivers. A quick visit to the NVIDIA forums lead me to a post where a few other individuals were having the same issues with the latest drivers as well.
If you are playing COD:UO then you should hold off on upgrading your graphics card drivers and stick with the slightly older drivers for right now. I uninstalled the 191.07 drivers and installed the 190.62 drivers from the “beta and archived drivers” page and now all is well again. I will test the future releases of the NVIDIA drivers to see if this will continue or if this is just a bug in this version. Lets hope it is just a bug!