System: Intel Core 2 Duo overclocked to 3.4Ghz, 3GB Ram, Radeon HD6770 1GB.
O/S: Windows XP Pro SP3
First of all, I installed Crysis 2 before upgrading my video card. Once I had the new card installed, the next time I opened the game, I was automatically upgraded to v1.9. Then, I installed DX11. Now, when I go to graphics options, I cannot set my resolution (it is grayed out) and I cannot enable DX11 (says disabled and grayed out). Anyone got any ideas? (with the old card, I was able to set resolution, but game would not play more than 5 seconds...that's why I upgraded card)
Do you think I need to start from scratch, and reinstall Crysis from the beginning, now that I have a compatible video card?

Did you install your graphics drivers?

Yes, of course. Installed driver disk, then was prompted to go to website and get latest driver, which I did.
Then, when I ran the game, I was prompted to upgrade Crysis 2 to version 1.9. Once that was done, I
downloaded and installed DX11. Like I said, the game plays fine (no lag or lockups), but I still can't set my
resolution or enable DX11. Do I need to have a 64bit OS for DX11??

Yes, of course. Installed driver disk, then was prompted to go to website and get latest driver, which I did.
Then, when I ran the game, I was prompted to upgrade Crysis 2 to version 1.9. Once that was done, I
downloaded and installed DX11. Like I said, the game plays fine (no lag or lockups), but I still can't set my
resolution or enable DX11. Do I need to have a 64bit OS for DX11??

> O/S: Windows XP Pro SP3
Not supporting DX11. Go win7

With that hardware i would not bother going DX11. Need at least tri/quad core cPU with more powerfull GPU.

Can I go back to DX9 simply by uninstalling DX11 through add/remove programs?
Or should I just cut my losses and install Win 7 (friend just gave me a copy)