Every time i download the game i get a corrupt file error.
Is this normal?
Im using the gog downloader.
Any solutions to this?
I use firefox and windows 7. Sorrry for my english.

I have not had any problem with the GOG downloader, but I have a very stable Internet connection. You need an Internet connection that will stay up long enough to complete the very large download; if it breaks down or times out, you will probably end up with a corrupt file.

I have a very stable connection. I reinstaled gog downloader and now it crashes a few minutes after starting download.
So yeah dunno gonna try from normal download and hope for the best...

I am having this same problem! I had originally downloaded and played W2 from when it first came out. I just decided to play again and so wanted to re-install but I keep having trouble.

Every time the download goes fine, the integrity check passes, the install begins, then at some point I get "An error occurred while trying to copy a file . . . . The source file is corrupted."

I have tried like 6 or 7 times over the past week, using GOG downloader as well as manual download. Every single time I get a problem.

I am a regular GOG user and have never had trouble with other games (or even with W2 before now).

Really puzzled how to get around this.

I contacted support and they suggested I check for hard disk errors (did that and none were found), try manual download (tried that and I get the same error), and disable anti-virus (did that too and still same problem).

Does anyone have another idea?

This problem is solved for me - the folks at GOG were very helpful throughout! Many repeated attempts to install failed. Then I tried one of my other computers, with similar specs running Win7, and it worked first time. I am now trying to figure out if there is something wacky with my RAM or hard disk on the computer that it failed on. I have no problem playing other games on that machine from GOG or Steam, so I'm puzzled why Witcher2 didn't work. But, I'm up and running on a 2nd machine. BTW, the same downloaded files used to install on the 2nd machine FAILED on the first machine, so clearly there is something machine specific going on.

I had this issue aswell, for me it was duplicate folders in the download path causing it.
I had the downloader set to program files\gog.com\gog downloads, and somehow there had been created 2x gog.com folders in the pogram files folder. Must have confused the downloader since it defaulted to win7`s standard download folder and threw errors everywhere when i tried to start the setup file.

After i removed one of the gog.com folders from the path it worked after i redownloaded it.
On a side note the only game in one of gog folders was Dungeon Keeper, its good to be evil i guess.