there seems to be no point in actually manually downloading the DLC files from another machine.
it seems to work ok with the update patches, but not the DLCs (well, for me anyway)

I got a friend to Download the updates and the DLC files for me from his client (and yes i have purchased them all)
so what i did was install Witcher 3 from discs, and then ran the .exe for the updates.

this updated my game from version 1.01 to version 1.10. i then did the rest of the updates from the GOG client.
that seemed to work fine. I then ran the exe for the 1-16 DLC... it installed and on the gog client it wasn't available anymore on the menu on the right anymore... so i assumed it was installed.

Then when i clicked on more (next to the play button) and checked under DLCs installed, the option for the "Free DLC program (16 DLC)" was unticked so i clicked it and it is now downloading the 500 mb of it again.

I have the exe for hearts of stone aswell, but that didnt seem to work neither. it installs, says its successful, but then still downloads it again anyway.

I want to still get Blood and wine, but i want to download it on another PC and then bring it home and install, but i dont want to go through this again.

am i doing something wrong? or in the wrong order or something?

Why are you using different pc's to dl?If to save time or whatever then maybe you should use your own pc and have no trouble even if it is slow.

Well, for one I have a SLOW internet connection, so downloading 8+ gig will take atleast 4 days.
and secondly, what if the PC im playing on isnt even connected to the web permanently?

The answer is don't use Galaxy. The client uses totally different install files to the manual ones. If your connection is so bad as to have to get friends to download the manual files, then you should stick to installing, and updating the game manually.

Okay,so it takes 4 days.That's not a long time too wait.I have waited longer at a bus stop:-)