Enable Directx 9 on Geforce Go FX 5700 win7

"I've heard more about DirectX changes helping against problems with Windows 7, so I think it would be a good idea.

Perhaps try installing the DirectX End-User Runtime Web Installer:
The Microsoft DirectX® End-User Runtime provides updates to 9.0c and previous versions of DirectX — the core Windows® technology that drives high-speed multimedia and games on the PC.

Something is preventing me from reading this page, but take a look at this

At least your video card should support DirectX 9 (from their site):
Microsoft® DirectX® 9.0 Optimizations and Support
Ensures the best performance and application compatibility for all DirectX 9.0 applications.

Note: check how much system resources your using, else you'll have to turn down some more settings. You probably have 512 MB RAM (edit: 1 Gb, still not awesome for what we do nowadays), which won't make you're life much better..."