I Bought Broken Sword 4 from here GoG and the game runs very slow. It's like 15-20fps and changing resolution or graphics doesn't have effect. I have tried running in compatibility mode, running with only one core and running in window. No matter whether is use 1920x1080 and highest settings or as low settings as possible, the game runs identically slow. I Also tried compatibility settings in games compat.ini. Years ago with my old system(AMD3500+, 7950gt, win7) the game demo did run quite well with bit lower settings.

Have anyone else noticed similar behaviour? Can my new hardware and platform(win8) in addition to poor game code do this? Lots of similar age or older games run flawlessly..doom 3, far cry, max payne 2, fear,...

Here is my current system:
i3-2120
GTX 560 Ti
8GB RAM
Win 8 x64

EDIT:
Solved by forcing software sound in compat.ini. Apparently I did'nt tried every setting, heh. I have M-Audio Audiophile 24/96 so looks like that gave problems.

The same problem here, under Win8. Your solution didn't help. Any ideas?

EDIT: GOG's support helped me! It works great after running in clean boot mode, descripted as below:

http://support.microsoft.com/kb/929135