I bought the special edition of Crusader 2 because the price difference was negligible and the description said that it came with Crusader HD. Where do I find either how to redeem it or where I can download it? I cannot find it in my library or any email with a code or anything.

Thanks Valer1us for that.

For others reading this, you need to find the CD key in your account on the gog website - I could not find it in gog galaxy.

Once I had activated the product, to launch the game using gog galaxy I had to open the Stronghold Crusader HD library entry, then click More > Other > Stronghold Crusader HD to launch the non-extremem version.

Obviously, you get the gold. Sorry for not seeing this sooner.

Thank you very, very much for assisting me.