I have no idea why would that error pop up, it indicates that the RERES.dll file that should be present in game's directory cannot be loaded for some odd reason (missing, corrupted?).
I've got the French version working on my computer and put it on Dropbox
. You can use it if you want. It also includes Creative ALchemy, which means you can have 3D sound and special sound effects, just as you would if you had a Windows XP machine with one of those Creative sound cards. You only have to make sure first 2 checkboxes are checked in Riot Engine Options on the Audio tab. You can access it by holding Shift while launching Drakan.
I can't tell how the game managed to break on your side since you made it to menus the first time. I know for certain applying patches can't break it. Maybe something's off with the CD you're installing it from? If this was Steam game, I'd just ask you to verify game cache, but in our case, we can only guess.
Helping over a forum is a bit inconvenient.