Crashing doesn't always mean that its the hardware's fault as often times its the software with the problem. Games are the most notorious programs to crash even the most rock solid hardware setups, it could be the game you play or even just a cluttered HD and a bunch of crap loaded on it.
If you keep your system maintained that should mean your software is running at the best of its ability and a crash would be most likely due to your hardware. Although viruses and, possibly even worse, adware can definately gum up a system pretty quickly along with improperly installed or uninstalled programs and aplications.