Hallo!
To copy the .dll-File into Unreal's Folder worked for me. Thx 4 the hint

I'm now running Unreal with Direct3D on a GF2GTS with the 23.11-Drivers.
Tried OpenGL but couldn't get Unreal running with this (haven't tried with the NaPali-Drivers though).
I have no sound-problems at all. I have a SB128 and i use the drivers that are auto-installed with XP.
If someone is interested in it: I meanwhile figured out i can join Unreal-Online-Games with NaPali when i copy the DM-maps into the NaPali/Maps-Folder. But Single-Player-Maps don't work. NaPali crashes if you try to join a co-op game.
But no need anymore for that. Unreal is running fine now. Thx again 4 the info
Greetings,
Xylander