hello i just got return to castle wolfenstein and after installing and clicking launch the screen fades to black then crashes and lands me at my desktop with wolfsp.exe has stopped working. does anyone known how to fix this?

You could try the unofficial 1.42c patch. Or you could use the ioRtCW engine port.

The easiest way is to install the game (GOG version or any other version) and just extract the ioRtCW files into the game installation folder. Then launch the game by using the ioRtCW executable instead of the original exe.

What I've done is created a folder for ioRtCW and extract the ioRtCW files there, then I've extract the data files/folders for the game from the GOG installer and put those into the ioRtCW folder. That way it all works without me ever having to carry out the installation of the game.