My keyboard doesn't work properly unless I choose QWERTY keyboard.

Image is from the start of tutorial. It shows strange commands instead of WASD.

You can always rebind the keys to your liking be editing the user.ini file to cope with most control issues (e.g. using the QUERTY scheme and rebinding to your actual keyboard layout).
This thread is a good source for infos about key binding:
http://www.gog.com/forum/the_witcher_2/keyboard_remapping_issues/page1

I actually solved this by reseting input settings to default.

I have no idead how or why this happened. It was my first time playing the game, I didn't mess with options.

Anyway - solved.

Thanks for letting us know.