I've been playing Stronghold Crusader HD (NOT EXTREME) for a couple of weeks now and everything worked fine. I had to access the game from the install folder because the default is Stronghold Crusader Extreme, but that was fine.
Today when I clicked on the icon on my desktop it said the file was changed or moved, and the game disappeared from the install folder.
I downloaded and re-installed Stronghold Crusader HD again (both from the offline and galaxy installers, as well as a system administrator) but still no Stronghold Crusader HD, only the extreme version.
Please advise as I would like to continue playing the crusader trial campaign I started...

The icon always directs to the extreme edition, but in the directory you can still run the Stronghold Crusader.exe. I deleted it for testing and Galaxy reloaded it.

Thanks but my issue is that the Stronghold Crusader.exe is missing - I've been running it from the directory since I started playing but it just vanished. The only .exe file is for the extreme version

Like I said, I deleted Stronghold Crusader.exe and Galaxy reloaded it. Have you checked the virus scanner? The cause can neither be with the installer nor with Galaxy.

More specificly, the AV's caratine folder.

Where did you install your game? If you installed it into the program folder Windows has a nasty habit of removing .exe files. Also, anti-virus programs will have a nasty habit of flagging and removing programs without telling your. I would be willing to bet that one of those two items got you.

just bought stronghold crusader hd no exe stronghold hd available. in "more" under manage installations show folder is unavailable ?? please help and in English a not tech can understand

Just go to the game's directory and run "Stronghold Crusader.exe".