Cpu keeps jumping up to 100% while gaming

[cloudxblue]

I've just now noticed this, so far it's happened with the Sims 3 alot... Built the computer last February without playing a game cpu is around 17 and then while playing the Sims around 30 then out of no where jumps to 100 and crashes the game or whole system to where I have to a hard shutdown or it tells me something happened and I have to restart my system.

So far last time I tried to play the Sims I played 3 minutes not including the loading untill it crashed my whole system. Does anyone know what this could be

 

[cloudxblue]

So this ONLY happens when you play the SIMS? No other games or programs??

No I'm on the computer everyday I just played Southpark for 3 hours plus 4 other games seems like Sims crashes when I click the fastest speed

 

[cloudxblue]

So this ONLY happens when you play the SIMS? No other games or programs??

No I'm on the computer everyday I just played Southpark for 3 hours plus 4 other games seems like Sims crashes when I click the fastest speed