deni28: is there anyone left i been trying to get it to work for 2 days help please
I'm sorry I haven't been any help. But I have downloaded the game three times from GOG, with no errors, incomplete downloads, or corrupt files on any attempt. That includes two downloader runs and one manual download. So it's not a universal problem.
It is an extremely taxing download, and if your Internet connection does not maintain flow long enough to complete it, you will fail and end up with corrupt files.
Also, if you are sure you have clean downloads (comparing file size and hashes is quite good enough) but still get variable install failures, I would suggest going back and looking very carefully at your memory. Ordinary memory testers, even memtest86+, frequently miss bad memory, and the surest way to get a variable install failure is to have a stick of intermittently bad memory.