I've very recently bought Painkiller Black Edition, and in general it works great for me.
There's just this extreme Screen-Tearing I can't seem to get rid off.
I forced vsync through the control panel, which not only didn't work, but also did not limit my framerate.
Limited the framerate per console ingame (60 Fps, as I'm playing this on a relatively weak laptop with a 60 Hz Monitor), didn't do anything.
Sooo, the Tearing just stays the same, no matter what I do.
Has anybody else experienced this and/or knows a solution?
Thank you in advance.
Cheers

Thanks for the answer my dude.
Sadly (in this case) I already play without compatibility mode enabled, as it works perfectly (Thanks to the unofficial patch, I guess).

If you have an Nvidia card that is atleast Maxwell architecture or above (GTX 750 and up) then you should enable "fast sync" in the control panel for this game. Regular vsync does not work well at all with this game as it causes weird framerate slowdowns. Fast sync allows the game to run at a really high framerate and then chops out all the frames that the monitor can't use thus allowing the game to keep going fast like it wants to so you don't get the bad lagging that happens with regular vsync. Also your experience will be completely tear free.

I had exactly the same problem, but I have been able to solve it using dgVoodoo 2.71.3 with DirectX emulation.

Download the application, unzip it and then copy following files (dgVoodoo.conf, dgVoodooCpl.exe and MS\x86\*.dll) to Painkiller Black Edition\Bin\

Run dgVoodooCpl.exe and go to the DirectX tab.
Set VRAM to 2048MB, check "Force V-Sync" and uncheck "dgVoodoo Watermark", leave the other settings to their default value.
This solved the screen tearing issues.