Programs you'll need:
Cdkey mpq shell file
. NOTE: This is a banned cdkey. It does not work. It is simply here to give you a mpq file to put your key files into.
- Install the 26 char version of Diablo II (whatever came with your keys).
- Open d2char.mpq in MPQ Editor, select "Open the MPQ in read-only mode" when asked, leave all other options as is.
- Go to dataglobalcharsamcof and extract (drag and drop) amblxbow.cof
- Open d2sfx.mpq in MPQ Editor, select "Open the MPQ in read-only mode" when asked, leave all other options as is.
- Go to dataglobalsfxcursor and extract (drag and drop) curindx.wav and wavindx.wav
- Create a cdkey mpq file with Serby's CD-Key Change using a 16-char key (doesn't matter what key you use or where you get it from, there are several cdkey lists and keygens)
- Open the cdkey mpq file, leave all options as is and make sure the "Open the MPQ in read-only mode" is not checked.
- Put the files you extracted back in the cdkey mpq file (drag and drop) overwriting the files present. When adding the .cof file just leave the settings as is. When adding the .wav files, change the .wav rule to add as a "Data file". Make sure "Compression method" reads as "Compress" and "Encrypt file" as Yes.
Your cdkey mpq file should now have the key you installed the game with. Repeat as needed (you will need to install from scratch for every 26 char cdkey you wish to install).
Edit: Fixed typo amblxbox.cof->amblxbow.cof
Edit: Added a shell cdkey mpq file. Removed serby key changer.
Edit: Clarification abt how to handle multiple 26 char keys.