A
post on the Witcher 2 Website has workarounds for some issues in
The Witcher 2: Assassins of Kings to help players out while waiting for the patch
planned for next week. They discuss difficulties with activation codes, CRC errors on installation, the game failing to launch, poor performance on high-end GPUs, and ATI-specific issues. There's also
a separate note for folks with CRC mismatches downloading DLC, saying: "We are aware of that problem and we have a solution already prepared in the upcoming patch. Until that we ask you kindly not to download the DLCs until the patch release as it won't work without it."