1. Problems installing Dragon Age: Origins under Windows 7
An user on the official forums found the solution: if you encounter any trouble installing DA:O under Windows 7 (x64 especially), simply right click the game’s setup file and click Properties. Select to run the program in compatibility mode for Windows XP (Service Pack 2) and run it as an administrator. Ignore any .Net framework errors and install the game!
2. Dragon Age: Origins keeps crashing under Win7 x64
It is reported that this might be a problem with the nVidia drivers. So if you have the latest drivers installed (as you should) try downgrading them to the 190 series and see if that solves your Dragon Age: Origins problem.
3. Keyboard stops responding after playing Dragon Age: Origins for some time
It might be the fact that you have other programs running in the background (like a firewall that pops up a message). Try using Alt + Tab to switch to your desktop and see if there are any running programs in the background. It would be best to turn them all off before starting to play to avoid such freezes from happening.
4. How to fix “failed to initialize physx” error message?
There seems to be only one solution to this error: uninstall your physX drivers and then installing them again by running the installer from Steam\steamapps\common \dragon age origins\ redist\PhysX
Hopefully you have no other Dragon Age: Origins problems and these solutions will help you fully enjoy the game. Have fun!