It seems that you're using an outdated browser. Some things may not work as they should (or don't work at all).
We suggest you upgrade newer and better browser like: Chrome, Firefox, Internet Explorer or Opera

I recently installed Witcher 2 on Windows 10 (Version 2004) with an AMD Ryzen 9 3950X (16 Cores/32 Threads).

The launcher starts fine but launching the game from the launcher fails:
Only the wolf logo splash screen shows and nothing happened no matter how long I waited. (No crash or error message)
The Task Manager showed "witcher2.exe" running in the background with RAM usage frozen around 200MB.

I spent several hours trying to fix this and only after a long while I found in a forum somewhere in a burried comment some hint and so I decided to post this solution so it could be more easily found.

The issue seems to be with my CPU having too many cores/threads available since I played it a few years ago with exactly the same system except that I upgraded my CPU earlier this year.

The solution to my problem was that I had to manually set the Processor Affinity of the "witcher2.exe" and the game started just fine. In my case I set the game to run on my first 16 cores/threads but I don't think it matters how many or which cores you assign it to as long as the affinity isn't set to the default "All Processors"setting.

One thing to take note of is that affinity can only be set on running processes and Witcher 2 will crash if you change its affinity while it's running. To circumvent it you'll have to start the game (witcher2.exe) or its launcher via a CMD command to set the affinity at startup:
start "" /affinity 0xFFFF "<Path to game folder>\Launcher.exe

0xFFFF is the hexadecimal bitmask which indicates which cores to run at. in my case its the first 16. There are some processor affinity calculators online which will give you a mask for your settings.

In my case I wanted to play Witcher 2 with the GOG Galaxy Client so starting the game from CMD wasn't an option. Processor affinity is inherited from the parent process.
So in my case I created a desktop shortcut to the GOG Galaxy Client which launches the GOG client from CMD and sets its affinity so when I start Witcher 2 with GOG it'll have all the GOG features (achievements, playtime etc) and the startup fix applied:
C:\Windows\System32\cmd.exe /c start "" /affinity 0xFFFF "C:\Program Files (x86)\GOG Galaxy\GalaxyClient.exe"

I hope this post might help some people who run into the exact same problem. :)
Post edited August 13, 2020 by DamIDhagor