Hmmm... maybe a hardware issue? I shut down errant processes all the time, and aside from the occasional momentary hang, it's fine. Come to think of it, I don't think I've had to reboot windows due to a (software) crash in years.
Congratulations. You own the only reliable Wintel box on Planet Earth. I'm not talking about just one box that I own, I'm talking about literally thousands of different servers and workstations that I've worked on. I do Field support work (15+ yrs) for a very well know storage systems company -- robotic tape libraries, disk arrays, etc.. In my experience, when customers report hardware problems (tape drives not being recognized, LUN mapping problems, unable to initialize robotics, unknown path to host, storage unit unavailable, etc, etc, etc...). I could go on for days.. But the problem is almost always software, in spite of what Microsoft or anyone else says. My experience is mostly with Veritas (sorry, Symantec) NetBackup, Legato, Tivoli TSM, Comvault, BackupExec, Amanda, and some non-public proprietary storage applications. Netbackup on a lean unix box is the best of many bad choices (read: windoze/linux).