Hi McJakub, welcome to FH2 forums!
How did you install FH2? The proper order should be:
first: BF2
second: BF2 patch 1.41
third: BF2 patch 1.5
Now BF2 should run normally, try to create a local game, or try SP. If it doesn't work, fix the problem first before you try and install FH2.
If you're gonna intall FH2, download the Launcher and then follow the instructions.
I hope this will help, I don't really know much about the dll file you mentioned.