I avoided Witcher 2 for a while, but I wanted to catch up so I can do Witcher 3... So I labor back at it, and after arriving at the first chapter (damn long prologue)... it just kinda locks up. Randomly, I can't replicate it on demand, and it happens whether I'm fighting or walking around or trading. The graphics lock, background sound continues, have to tab out and terminate the process. Running full vanilla. It happens frequently enough that it is impossible to play.
The usuals (drivers, background processes, reinstalling) don't help. The outlier here is that it never locked up in prologue.