I cannot install sacred gold. The integrity checker runs and then nothing happens. Task manager shows the installer in processes and nothing continues.

Hi!
First, try rebooting your computer. Maybe something is running in the background that blocks the installer.
Then, if that doesn't help, de-activate your anti-virus software: sometimes they interfere with non-risky programs as well. After proceeding with the installation, you can re-activate it, of course.
If even that doesn't help, download the installer again.

Depending on security permissions, you may also want to try and RunAs an administrator.

Probably "Installation and / or launching issues" from Support articles will help:
http://www.gog.com/en/support/sacred_gold

Try waiting for the installer to pop up again after the integrity check. It takes quite a while.

You mark any of the above posts (ehich you think was the best answer) as "solved". Then the thread will get this status as well.