So I just bought the HoMaMV pack during the sale. When I launch it the game starts in some other language that I don't understand and I don't know how to switch it to English! Any help would be greatly appreciated!

Sorry don't know how to edit the original post but the whole game seems to be in another language (manual and all). Is this an over site on GOGs part or mine??

If it helps it looks like Spanish

Update: A redownload seemed to fix the problem

Heroes V is one of the games that has different installers for different languages. Seems like for some reason you downloaded the Spanish one instead of the English, and when you redownloaded you got the English installer. If you still have the first installer files, you should notice that they say setup_homm5_spanish_2.0.0.22.exe instead of setup_homm5_2.0.0.22.exe
Some of the games have one installer for multiple languages, some have different installers for each language.
Hope this helps explains why the language wasn't in English and that it prevents further confusion with other games :)

Thank you for the answer. It looks like that is exactly what happened. It caught me off guard since when I clicked to download the link said English. I just uninstalled it then redownloaded and reinstalled it then happiness.