The support page forms are apparently not sending and instead loop back to the start. Here is the text of the ticket that needs opening:

I read the support article on windows Vista/7 install problems (although the article appears to apply only to Vista) but I don't believe it is the same problem. The downloaded file is a binary file (setup_gothic3-2.bin). I first tried downloading it with the GOG installer but it stalled after about 10% so I used one of the mirrors and my Firefox downloader (one click). Before I panic (actually, just download it again), I'd like to confirm that this should be an executable file. Apparently, I cannot open .bin files but that is a PC issue, not a game issue.

There should be an exe file. The bin files are just additional if the setup would be larger than 2 GB otherwise. If you don't have an exe file, then your download isn't complete.

This is where you're going wrong. They're not mirrors. You need to download all the links, so you end up with:

setup_gothic3.exe
setup_gothic3-1.bin
setup_gothic3-2.bin

etc ... (I don't own Gothic 3 on GOG, so don't know how many bin files there are).

Boy, that is just plain weird! I tried again with the second one and got the execute file and a "corrupted file" message - guessing due to the lack of the third file. OK, all three. I feel confident that'll work. I can't download until 2300 hr due to having a satellite connection (for four hours, I can download as much as I like) but I'll let you know if I was successful tomorrow.

you dont have any problems with other big files? dont think a satelitte is the best of internet connections. but yeah you need all 3 files.

I did have success once all three files were there.

I think some of the forms did get through - I received a pair of e-mails from two different teams. However, there was no indication that I saw of success until the e-mails arrived as the page just looped back. Won't know if this is consistent until I need support and, frankly, that is fairly rare as you guys have things pretty well covered.

http://www.gog.com/en/forum/general/is_there_a_problem_with_the_contact_us :)