The patch from The Adventure Company was to prevent the game from using more than one processor or core or Hyperthreading -- which caused errors because the game wasn't made to handle more than one processor.
You can get the same result by using compatibility mode.
GOG should have the patched version of the game already, and by putting an old patch from the now-defunct Adventure Company website you run the risk of getting an "insert CD" error when you start the game.
If you REALLY want to try that old patch, you can find it at the web archive ***here***
I tested the link (the "HERE" near the bottom of the archived page), and it does work to download a 3.7 MB file called Syberia_sp3.exe