next time, if there is one, check event viewer and see what is failing. Also, exact problem and what its doing would be helpful. As in, does it just restart with no screen? Lock up and if it does, is it online only, apps, games, etc. The more info the better. What was the last thing they were doing, etc. To let you know, if its crashing via a reboot then disable autorestart after system failure (rt click my computer, properties, advanced, and then startup/recovery and disable it). This will freeze the system and it will have to be power cycled by hand, BUT you will now at least get an error to pin point what the problem is. Post them and event vwr in detail.
If you argue with an idiot he will drag you down to his level and beat you with experience.
I am not a fast writer.
I am not a slow writer.
I am a half-fast writer.