Runtime errors are errors in the program detected during its execution. In this case an error message is given and a dump of the call stack of objects is generated.

Does your cousin have more information on the type of stack dump. When she gets the error there should be a bunch of numbers following the stack dump..
I in fact have never gotten a stack dump in windows XP. Previous versions were notorious for it.. among other errors.
Once I have the complete stack dump information I can offer a fix or at least a suggestion.

She should try the following as a general guideline,
make sure she has all her drivers updated.
check her hardware, including her ram, HDD, etc...
She might run a chkdsk in the command prompt.
She might also want to see about getting a patch for the game and making sure the game is updated.

Further she might want to make sure her hardware is compatible with the game.
Last she might try a motherboard and graphics card BIOS update, but this is very risky and can cause your PC to become inoperable..
Just some general advice.
I would say if possible to update to windows Xp, I think the home version update is only $99.00 US..
If that is not possible then try the previous suggestions.
BB