Okay, it's working. Thank you!
And yeah, turned out I already had WinZip, but for some unknown reason it wouldn't open the 2.77 7z file. *shrug* I ended up having to download 2.77 two or three more times, try it, and delete it before it finally worked. There's still a funny little problem with the wall sets -- the right-hand wall doesn't show up in the game. Don't know why, but I'll figure it out or work around it somehow.
I hate to bring up another problem, but only slot 2 of the wall selections seems to work, at least 2/3 of the way. Any other wall slot that I load with a wall of my creation and place in the game, I get a segmented view like looking at the wall file. It always has a window or a door in it, not placed correctly and not anything that I have loaded. And the left-side wall of slot 3 says "wall by Manikus" and the left side of slot 4 says "wall by Dionykos." Any other slots that I load are segmented but don't have anyone's names on them. I cleared ALL the slots and reloaded them, but they still do that. What have I done wrong? I want to point out again that these are walls I have made (well, using textures I found online), so they shouldn't have your name on them, even if I do have the format wrong somehow, which I clearly do. The format I'm using in the wall generator is 1024 wide, and DC hyper. Is hyper correct? I also tried DC standard, which looked even worse.
Okay, I tried loading some of the walls that you offered, Manikus, and got the same segmented thing.
Wall made by Manikus, screenshot of front and left wall:
Wall made by me, screenshot of front and left wall (slot 3):