What i've done with my german version Step by step:
1. Rename your file which describes your system requirements (in my case it was info.rtf) to readme.rtf.
2. The installer will ask you for some .wav files. Just create in the same folder those files with exact the same name.
3. Last it asks for a dwint.dll or something like that in a folder called 1033. My folder was 1031. Rename that folder and start the installer again.
Worked for me.
worked 100% for me.
1.) I used a fresh install of the German version
2.) Then I renamed info.rtf to readme.rtf
3.) I created the two missing wav-files upfront by copying an existing wave file twice and renaming the two copies.
4.) I copied the folder 1031 into a new one called 1033.
5.) Install the 4.86 mod