If Trainz keeps freezing after you restarted it, it's a possibility the database got munched. I recommend you go into Content Manager and run a database repair.
The problem though might be more insidious and maybe related to a hardware or OS issue. I recommend you do some system checks first such as a chdsk (scandisk) first, and perhaps some clean up.
If the freezes continue after everything, I'd look deeper as this could also mean a bad hard drive, a badly corrupted OS, or even bad memory.
John
