CTD and freezing with sound loop in l4d, rollback time.
I've not had CTD, but the freeze/sound loop thing in L4D seems to be a common problem with Nvidia cards in general. I've had it crop up from time to time regardless of driver version. When it happens you can resolve it by doing ctrl-alt-del (alt-tab won't work), choose to open task manager so you're placed on the desktop, then close task manager and re-maximise L4D from the taskbar. Goes right back to normal again.

