Retail requires installation via Steam, which uses the 5x5 key.
Very well, if I send my steam key to Taleworlds, will you send me 4x4 key back?
I have no Steam on my computer and will not install under any circumstances.
OK, since there was no answer, I tried installing that Steam client. It activated the game successfully, but I still cannot get the 4x4 cd key for my game. Do I need to reinstall it using Steam or what?
Ok, another update.
If you are unsuccessfull enough to first install the Warband, then play and then buy retail copy, here's the way to get rid of cd key problem.
1. Download and install Steam client.
2. Create new Steam account, validate it etc.
3. Launch Steam client.
4. Inside Steam client, navigate inside menus to 'library' and then click 'activate the game'.
5. Inside Steam client, in the dialog window that will appear, input the 5x5 product key (the one printed on back of the manual cover).
6. Still inside Steam client, go to 'library' and select Warband. Its status will be 'not installed'.
7. Right-click on Warband, select 'install'.
8. Let the Steam client to start downloading Warband installer.
9. After it started downloading, pause the download. You don't want to wait for ~850 MB to download.
10. Right-click on the listed Warband again. Select 'properties' or 'about' or something similar.
11. There should be a page describing what Mount & Blade Warband is, and on the right side of description, there will be menu.
12. From menu mentioned above, select 'CD key'.
13. Dialog window will show you CD key.
14. Copy it to clipboard (theres a button for that).
15. Write it down on a sheet of paper. Save it somewhere safe.
16. Launch your previously installed Warband.
17. Activate Warband using the CD key obtained in 13.
18. Exit from Steam client.
19. Uninstall Steam client.
20. Enjoy your registered Warband
That's all!
Worked for me.