How old are your components? (mainboard, cpu, psu)
Any overclocking?
What do you mean by "pc crashs" - game goes CTD (crash to desktop), or your whole PC does a hard reset?
If it's a complete "crash", then it's most likely a faulty driver, or hardware issue.
By your description i'd bet my money on the latter.
Don't compare it to other games, it's just a matter of load (stress on your hardware basically). COH2 is known for being quite insanely resource hungry - that's why i prefer to call it "playable stress test" 
Check windows event logger for the cause of the crash.
Monitor the temperatures and voltages in the background, i'd recommend www.aida64.com/downloads - has a fancy graph tool as well - or anything similar.
Btw.: do you use vsync?
My pc are two years old, almost that.
When i say pc crash i mean my pc turn off and turn on again automatically.
For me, it's seens something in power supply and VGA, because the temperature its fine.
i've tryed both...with and without vsync ...and makes no diference to me.
I gonna try aida64 and come back here with news..thx a lot for the atention.