There's an error in one or more of the files. It doesn't make sense to download them again and again using different methods.
We have to wait for a solution by the GOG.com's support team.
I sent them this message:
from: vanchann sent on June 02, 2010 17:24 UTC-4 follow up
Greetings from Greece.
The file "setup_kings_bounty-2.bin" seems to be corrupted.
I downloaded the file twice and have the same notification of integrity fault.
Please check the game's files integrity.
There's already a thread about this matter: http://www.gog.com/en/forum/king_s_bounty_the_legend/corrupt_file/_/last
No hardware information entered
Maybe they'll post a solution here. If they just answer to me, I'll post the message here as soon as possible.
You may contact them too if you like.