I also try to run this on Win11 and I can't get it to work.
Just to describe the problem:
The first freeze happens when the initial video is loaded. The screen is either black or a frozen logo, sound is repeating on this one. Like a broken record. Sound will run normal on all other freezes though.
It freezes again for me when the video shows Altair having killed the guys doing the hanging.
Within the menu there are freezes where the menu is just unresponsive for like 2-5 seconds.
Within the game it feels like it freezes when it has to load a new animation, a new voiceline, anything new. Then the video will either pause everything or just the video but play the audio correctly. Say someone says a couple of lines.
It will play the first line animation and sound fine. Upon loading the second it will pause the video but play the sound fine. Since the video was paused it will play the animation now, you only hear background music and once the animation that belonged to the already played sound finished it will then play the third lines sound and animation.
When walking around somewhere I think it just freezes because it has to load something in.
Hardware shouldn't be an issue. I have an 8core Processor, 32Gb Ram, SSD, 6Gb gpu.
The IP fix did not change anything for me.
It does not matter if I run the game with the dx9 or dx10 executable. Windowed or not does not matter and graphics options do not change anything.