I've searched all over the internet for the answer to my problem, but I just can't figure it out. I took the following steps:

1. Installed WA, doesn't work due to black screen problem.
2. Installed Beta patch, can't find installation directory.
3. Added a PATH data in the Registry pointing to installation directory.
4. Installed Beta patch.

But now when I run the game, it says I need the cd in the drive (no matter if it's in or not). I've also tried the other patch, but it just makes the game unplayable. Any tips?

Where did you buy the game?

On ebay. It's not the Sold out version, as far as I know it's the original version.

(If I make a mistake here somebody please correct me).

If you totally uninstall the game, then reinstall using the CD the only patch you need to apply is the very latest 3.6.28.0 (http://wa.team17.com/main.html?page=supp&area=upda&file=15) patch, as long as you are connected to the Internet while doing so. The patch then downloads and installs anything else that it needs to.

(If I make a mistake here somebody please correct me).

If you totally uninstall the game, then reinstall using the CD the only patch you need to apply is the very latest 3.6.28.0 (http://wa.team17.com/main.html?page=supp&area=upda&file=15) patch, as long as you are connected to the Internet while doing so. The patch then downloads and installs anything else that it needs to.
Correct.
AFAIK, this works for all CD versions including the original ones (EU & US) and budget versions like Sold-Out or GreenPepper.
It also works with the Czech localized version. I don't know about the Russian localized version though.

All righty, that seems to have fixed it. I guess I had an old patch. Thanks a lot for the help.