Halo does that to me. Or did anyway. I had horrible text lag, and about once per map rotation it would say "Team Race" or whatever it says at map start, over and over, and it would freeze up. I could Ctl-Alt-Del and kill halo.exe and restart.
I reinstalled halo completely, and those problems seemed to go away. I then got a new computer, so I'm not 100% sure it was fixed.
So reinstall is one option.
If it's happening on other games, then maybe video card overheating? Does it happen right away or after playing for awhile. Maybe clean the fans, update the video drivers, or turn down the settings a bit.
You could run a chkdsk /f on your hard drive, defrag the disk and do a full virus/malware scan, which never hurts, but I doubt would make a difference to your problem.