I already have Witcher 3 installed and up to date on my computer. I installed it last year and finished it. I purchaced the game through GOG and am registered through GOG. Installed GOG Galaxy today and now its redownloading the whole stinking program!!!! WTF! I hope my save files will still be there. Not a very good 1st impression Gog Galaxy

First of all if you installed the game "last year" it's definitely not "up to date" as even the basegame without hearts of stone and blood and wine was getting several updates in the last few months.
Secondly if games are already installed before installing GOG Galaxy there is a "Scan and Import Folder" option in Galaxy which it seems like you didn't use.

You are aware its possible to update your games purchased through the Gog web page without installing the clent. Which I happed to do just last week. so I guess it is "up to date". I found the scan import folder after picking around. An option which wasnt made very apparent.

Yes I'm aware of downloading the installers :) - didn't became apparent for me due to the "installed it last year" so i came to the conclusion that the last time you actually "updated" the game was actually sometimes last year when you installed it - my bad.
Hope the scan and import folder option saved you a long download now!
Cheers.

There have been quite a few patches to the game and its DLC since it was released, if you just installed Galaxy then Galaxy will detect that the game is out of date and automatically update it to the current release by default. If you do not want it to do this, you need to disable auto-update for each game individually, however there is a bit of a catch-22 because if you install Galaxy, it will start updating your games before you get a chance to disable auto-update.

If you want to stay using an ancient version of the game then you can start up Galaxy, quickly click on the game and go to settings and disable auto-updates for it, then exit Galaxy. In theory that should terminate any update it was in the process of trying to do. Do that with each game you want to stay on an outdated version of.

Having said that, CDPR has fixed a tonne of bugs in the game and added a whole bunch of fantastic new features to the game since last year including revamping the user interface significantly. It's highly recommended to use the current version of the game (1.31) as it's significantly improved. If you don't want Galaxy to update it and prefer to do that yourself, after disabling auto-update for the game as per above, you can download the patches manually and install them, then start Galaxy after. That assumes you're using version 1.10 of the game or newer already, otherwise you will need to download the game's full installer instead as the only patches still available require version 1.10 or newer to patch.

Another thing worth noting is that there is a race-condition that can occur with Galaxy when it is running and you install a non-current version of a game from an old installer - even if you have patches for it. What happens is that any Galaxy-aware game installer will install the game and then invoke GalaxyClient to register the game with Galaxy. At that point if Galaxy is running it defaults to auto-update and will begin scanning the game's files to compare them with GOG's server and see if a new version is available. Galaxy has no idea if you already have the standalone patches or if you plan on installing them right now or an hour from now or ever, so it just happily goes ahead and starts updating the game for you.

The only solid way to prevent that, is to always install games from standalone installers like this:

1) Check to see if there are new installers or patches for the game than what you have downloaded already.
2) Download any new patches you are missing, or a whole new installer as appropriate. Do the same for any DLC etc.
3) Exit Galaxy completely.
4) Install the game.
5) Install all patches for the game.
6) Install any expansions and/or DLC for the game.
7) Install any patches for the expansions and/or DLC.
8) Start Galaxy, it should already be aware the game is installed if the installer was Galaxy aware. If it was a Galaxy non-aware installer then you'll have to do a manual import.

Galaxy will still try to scan the game and compare it and download a few things (DirectX et al), it's usually only a few megabytes to a few hundred megabytes even though it may say otherwise in the UI. Either let it do that or disable auto-update.

HTH

Yo, skeletonbow, he noted he updated the game last week. :P

Yep, fully aware. I've had this problem with The Witcher 3 also and the solution was completely uninstalling it and reinstalling it as I mentioned in my above post. The problem annoyed me so much that I stopped using Galaxy for a while because it was interfering with my ability to play the game etc.

Attached full current file list from downloadable assets for Witcher 3... i installed them in the proper order in a VM, launched Galaxy from a fresh install on the VM and it didnt need to update as i installed the offline patches in the correct order... which took some time to figure out i might add.

Its entirely possible you missed a patch as this filelist is insanely confusing as to when and how to install everything to make it work.

But even then Galaxy did not detect a difference between my offline installed and the online install cache and did not update a single file... being a VM i did launch it but was unable to play do to crappy 3D emulation (didnt want to link up a 2nd gpu for a test) but it launched fine...

Check my filelist to yours ensure you have them all.