Ok, I played the game, and everything was fine, but when the 1.1 patch came out, it wouldn't install manually, so I've reinstalled the game, and when it starts to check out for updates, the same patch is installing over an over again. Now, I've read that in that case you have launch patcher.exe manually form My Documents, but when I do that, it says 'The Witcher 2: Assassins of Kings Patch Utility has stopped working'.

What should I do??

Same situation. Feels bad

On http://en.thewitcher.com/patch/ it says: If auto-patching during installation does not work for any reason, download the patch manually, based on your region/version by selecting one of the links below, then run the .exe file to update your copy of the game. Have you tried that?

Same problem on my collector edition.
I try the manual and the automatic, but nothing to do!
I put my serial start the update, download 29498KB, check, download, check download....etc

Maybe this will help: http://en.thewitcher.com/community/entry/35/#comment-212465107

you NEED to read on the 2nd section here: http://en.thewitcher.com/patch/

where is says: "2. If you are installing the game for the first time or re-installing it, the game will automatically patch online to version 1.1 during installation."

and after that sentence there are a bunch of patches to download... get the one for your version and install it!

had the same loop problem, I had to get the Patcher_ROW.exe (same file that kept downloading again and again forever) and install it. After that you can even register your game, I just did :)

Sigh. I guess ill try and reinstall the game again and see if that works

OK, I've downloaded the patch, installed it manually, and it worked! Kudos to all of you for trying to help.

Cheers..

I try the 2nd 5-6 times, don't work.
I try to launch automatic donwload, don't work.
Before the unistall i play the game....

flangers: before reinstalling remove the troll DLC file from folder specified in the link. It might work. If you don't have the DLC or it doesn't work then reinstall.
Please read this post carefully: http://en.thewitcher.com/patch/

If you already played the game then manually download patch specified in point 1 in the given post and install it.
If you did not play the game or have problems with the patch from point 1 reinstall the game and wait for automatic download.
If automatic download does not work manually download patch from point 2 in the given page.

i understand, i try all ways, but not work.
I remove the game again (thirs), tomorrow i try again.
Bye

Here's another solution:
http://www.gog.com/en/forum/the_witcher_2/use_launcher_to_activate_game/post28
http://www.gog.com/en/forum/the_witcher_2/ill_never_buy_another_game_from_gog_com_again/post28

Well. I reinstalled it for the third time and it took this last time..hooray

Did reinstalling and patching work? I am getting the same message about my an invalid or incomplete version and exiting. My installation was pure vanilla (no mods, only the troll trouble dlc) from the DVD's and I downloaded the Patcher_ATARI patcher which is supposed to be for the North American DVD version.