I want to download Deus Ex but the GOG.com Downloader would just end up giving me a checksum error on a chunk or part. Obviously, this is occurring because of a broken download. Something the GOG.com Downloader is made for in the first place.

I've tried at least 3 times or more before finally giving up and using the direct download instead. This time I'm using a download accelerator (DAP). It will download fine for at least 30 minutes (?) I'm not entirely sure about the timeframe because I leave it running on the back. But after a long amount of time has passed, I get greeted by DAP with the "Authorization required" dialog box prompting me to login. (Attached image) I assume this was because the download session has timed out. So I enter my GOG username and password but it doesn't accept it, probably because the server where it's downloading from is wpc.11df.edgecastcdn.net and not GOG itself.

With all of that said, I just want to clarify that my internet connection sucks. Is there any salvation for people like me who have hopeless internet connection but splurged on the holiday sale? I want to play most of what I purchase but can't because of the downloading issues.

Tips or help anyone?

Uhm... I don't have DAP (I'm on Linux), but have you tried using your e-mail address (one that you use to login to GOG) as the username? I do not even know if it will work, but there's nothing wrong with giving it a try.

You know that is actually an idea! I've always been logged on to GOG from the start and never logged out that I forgot I actually use email to login instead of username. Good one. :) Will try it out when this current download try fails again.

Okay, I just tried it, still doesn't work with email + password combo. :(

When the downloader was shit or didn't exist I used an accelerator, IDM (Internet Download Manager) and never had a problem.

Oh wow, I actually got to the end of it this time using GOG.com Downloader.

I'm now trying my chance if I can successfully (and finally) download XIII.

EDIT:
Okay, screw that, it's still corrupted even after it was marked as completed. :/

Sorry to hear that, and sorry I can't be much help either. I cannot even use GOG Downloader 'cause that damn thing with its .NET Framework does not work in Linux with wine.

These days I usually just use DownThemAll add-on in Firefox to download from GOG. The other day I was downloading Beyond Divinity. The download got interrupted in the middle for several minutes. Amazingly I could resume the download. Don't know whether it was due to the session being still active or I was just being lucky.

Maybe ask your friends who have faster internet connection to download it for you?

I just downloaded half of my game library using work internet which is blazing fast. :D Not the most convenient method but it works so I guess I'll have to smuggle my games via work then. :P

Why, that's what I also do here :-D

I just successfully downloaded this game using the GOG downloader without any problems. Are you overclocking by chance? If so, try disabling that. If not, I would recommend testing your computer memory using memtest86 as it is possible bad or malfunctioning memory could be corrupting random data in memory. Another possibility is corruption on-disk, in which case you might want to install disk SMART monitoring software for your motherboard/disk controller, or alternatively the open source smarttools software and use smartctl. Worth using these utilities to test disks and RAM from time to time just to ensure they're not experiencing errors or nearing death.

Hope this helps.

What you need to do is feed in a new source URL. Initiate a new download without starting it, then copy the URL from that and add/replace it on your existing download. I don't use Download Accelerator Plus so I don't know the exact steps required, but by doing this you should be able to resume the download every time.