strange lockup problem

[mlr]

every now and then when playing games my computer locks up i get a black sceen then a little box comes up saying signal not valid im using windows xp pro thanks in advance mlr

 

[HoLoCroN]

It could be a display driver conflict. The game might try to run at a resolution that the driver or the monitor doesn't support. Try downloading a patch for the game if available, and try updating the display drivers.