I bought Stronghold HD this morning, no problem with installing the game, but the french patch doesn't work. I have an error message in the middle of the process, then it finishes as if nothing were wrong, but when I launch the game it's still in english.

If you install the game in the Program Files (x86) folder you have to open the patch with administrator rights. If you installed it elsewhere maybe you have problems (like some guy with the german patch had) with your antivirus which blocks the exe. Then you have to add the file to your allowed files. Or your download is corrupted. Then you have to redownload. I hope one of this solves your problem. ;)

Game is not installed in Program files (x86) but in c:\GOG Games\Stronghold
Tried to run the file as admin : same problem
Not the antivirus blocking it because the patch proceeds until I got the error message : "the file Carte personnalisée - assaut sur Fougères was not found"
Tried to re-download it : same problem

I've the same problem (downloaded the patch twice).

The patch may have some issue with accented chars.

I've personally tried the two, it didn't work.

I've attached a screen of the two error messages displayed.

Here are the screenshots of the two error messages I got.

Same problem for me.

Same problem, but with the spanish one.

I don't know what "assaut sur Fougères" means, but in my path the file "¡A por las brujas!" (To (get/catch) the witches!) was not found, either, maybe is the same file?

I'll try to redownload it with the browser.

I got the same with the spanish pack as I posted here:

http://www.gog.com/en/forum/stronghold_series/error_when_i_try_to_install_the_spanish_lenguage_pack

After installing the French patch and getting the same errors as Ghadzoeux, the game is not translated at all (full english).

Nice, do it also with the spanish pack, please!