Technical problems and solutions!!! (all problems and errors are stored here)

[calonge]

the demo launch ok
but when I talk with Iron richards ,he open a entrance
and when I try go to the entrance the game crash to window
and when I try open the heroe menu crash to window and message:
/BM Render /rmode 2575irect X call failed -1-1D3DERR-invalidcall
Whats the problem? .I play fantasy wars with no problems at maximum
answer me ,please

My pc:
amd atlon 3600
geforce 6800 gt
ram:2Gigas
direct x9.0c
windows xp SP 2