I have DVD version of the Witcher 2 with Windows 7 x64. The game itself appeared to install fine but the patcher did not work correctly. I did try to install game under non "standard" directory on different drive than my system. Also I typed in the key as printed on the User manual. Pristine install of the OS did not help (no antivir etc). Each of the patches nagged about "...internal error...". I assume that it's some patcher temp file And yes - I tried more than one of the half dozen different possible patches, with new install of the game each time.
The solution for me was to use the "easy install" with preset path on the C-drive. Also when the installer asked for the key I simply left it empty. After this automatic web based patcher worked just fine. I hope that this information may help you others out there to get this great game to work...
(BTW - for any of you developing programs or patches for them: some one may have dedicated OS harddrives that they do not want to "pollute" with other applications. However, I seems that I had no other option here...)
