Embedded chip or plug in video card, either way it has driver software and some kind of control panel to set display options. Lower left corner of the desktop, click the START button, then RUN, in the little window type dxdiag. When the DirectX Diagnostic screen comes up click the Display tab, that will tell you what driver version your onboard video chipset is using. Dunno about win 7, but all versions from XP on back to 95 you right click an empty spot on the desktop, select Properties, then the settings tab and advanced, that will get you a tab that leads to wherever your video control panel is. Assuming, of course, that Win7 UAC will allow you to go there.
Other questions, your profile doesn't show a registered version of Trainz - what version or versions do you have? If it's a version with content manager, can you open a built in scenery object and view the mesh for that, or is that gray too? Something like;
Abandoned-Industry-Spline,<kuid2:33404:5068390:2>
Is best to test with, it's a good sized mesh and if you can't see that it confirms it's not a tiny off centered mesh getting lost somewhere.