Hi Andy,
I thought I was going to run into all sorts of issues if I installed it manually. Actually, I did (minor issues, actually), but that was because I didn't read all of the installation files.
Nonetheless, download the .zip files (both program file and language pack (unless you're fluent in German)), from the
4Images website, unzip them,
read the installation files under the docs directory, and install away!
There is one issue that the install files fail to expand on, and I made a note of it
here.
Good luck! It's a fantastic program once it's up and running.
Cheers,
Lawrence