Also, no details of your system, PC or MAC, Windows? XP/Vista, Mac OS?
If you mean the Need for Speed Most Wanted demo at;
then that is a huge file, 544MB, and if you have a dial-up connection you are going to struggle whichever site you try to download from. One small error in the continuous download checksum and the download halts with an error, so this is not necessarily a problem with Download.com but with your internet connection.
However I notice that on my own 10MBS broadband connection I am only getting 20-30Kbs when I attempt to download this file, and at that speed it will take over 6 hours. Since I am not willing to wait that long just for a demo, I cancelled the download.
It seems the Download.com severs may be busy, so if you have a broadband connection you may do better downloading from another source. If you have dial-up, perhaps a friend could download it for you and burn it to a CD?
Recently I was trying to download the NFS MW demo from CNET. I was totally frustrated to see after 6 hours of download (ofcourse wasting my sleep) from the site with 1% left to complete CNET threw a 404 (page cannot be found) error making it a huge waste of time and resources. Now I have a 546.81 MB file of no use because of this. Can there be a resolution for such issue? This really makes people to do downloads from CNET.
Why does this happen?
(I believe I took the wrong decision by trusting download.com more than EA site itself).