I have now tried several times to install the game, and the installation is always succesful. But after the installation i have to give my registeration code, and a small window which says "Checking for avaible content". After that, it opens a download window which downloads 112 MB of data. That is when my problem steps in. When the download is complete, it just resets the download progress, and keeps loading and loading the same 112 MB to my computer. Cant find any folder for that data or anything, so I assume that it does not save the data anywhere.

Any help with this, please? Been trying to solve it for 3 days now...

Manually patch your game to 1.3. The entire registration code thing was aborted and subsequently removed in the patching. All DLC is included in the patches, so you won't be missing out on anything.

If you're using a non-GOG version of the game, then use the 0 -> 1.3 patch. If you're using the GOG version, then download the 1.1 patch from your dashboard under the download links and extras, then download the 1.2 patch, then finally use the 1.2 -> 1.3 patch.

Link to patch 1.2: http://en.thewitcher.com/patch1-2/

Link to patch 1.3 (both versions): http://en.thewitcher.com/patch1-3/

And just for future reference, you don't have to type "Q:" in your thread title. You just check the "mark as question/problem" box under the title and it'll automatically create the "Q:" for you :)