After you have downloaded the offline backup installer files (usually one EXE and a bunch of BIN files), clicked on the EXE file, and chosen the preferred language for the installation process:

1) Click on Options in the lower left corner (first screenshot)
2) Specify the path the game in question should be installed to, in this case on partition e:\ (as opposed to the standard c:\ which should be avoided at all costs) (second screenshot)
3) Tick the EULA checkbox at the bottom, as well as (or not) the optional ones for the desktop icon creation or the file integrity check (not pictured) prior to the actual installation process
4) Click on Install
5) Et voila

Hm, weird. Normally the GoG installer installs games by default not into the programs folder, but into an own folder named "GoG Games". Looks like OP accidentally changed the installation folder to "program files".

The problem seems to be located between the screen and the backrest of the chair.

I suspect again that the OP and others are talking about different things.

The OP might be talking about downloading and installing GOG games with the Galaxy client. I have no idea if it installs them e.g. under Program Files by default, if e.g. the Galaxy client itself is installed there as well.

The others apparently are talking about the standalone offline game installers which one can dpwnload from the GOG account with e.g. a web browser.

It does. Galaxy by default installs games to:

C:\Program Files (x86)\GOG Galaxy\Games

So i'd agree with you that it sounds like the OP installed Fallout via Galaxy rather than the backup installers.

Ok, so I guess pretty much like e.g. Steam does.

Does Galaxy have an option to either tell it to install all games into some other drive/folder, or even game by game? I guess that is what the OP is looking for. Or is the only option to install the Galaxy client into the drive and folder where you want all your GOG Galaxy games to be installed?

Yes you can change where it installs games.

To do this click the GOG logo in Galaxy, then click settings. Click downloads, followed by the box called Game installation folder.

In there go to where you want your games to be installed (I have mine in D:\GOG Galaxy.) It will create sub folders for all games you install automatically so for example if you install Fallout New Vegas it would then be installed at D:\GOG Galaxy\Fallout New Vegas.

Ok good so that was the instructions that the OP was probably looking for. So as per RoboPod's instructions above, you can tell Galaxy to install the games elsewhere too, but apparently not game per game.

So now when you want to "move" your Galaxy game to some other drive/folder, you probably have to uninstall your game(s), change that Galaxy client setting, and then reinstall the games. Not sure if there is some manual workaround so that you could "move" a game without reinstalling it.

yes and yes

p.s, back in the day gog did install to program files by default and they changed it to gog games because it was making so many problems so if op has very old copies of the install files then that may be the root issue

1) Copy the installed folder (so copying the entire Fallout New Vegas folder for example) and paste it into your new Galaxy Installation folder.

2) Next uninstall the game from Galaxy right click on the game in your games list in Galaxy. Go to manage installation, then uninstall.

3) Then tell Galaxy to scan and import from the folder where we copied your installed game folder to in step 1. Galaxy should then check the game and create all needed registry paths, and finally say its installed.

To scan and import, click on the GOG logo and click on scan and import folders. Click on the blue button called Select folder then navigate to your new Galaxy installation folder. And click Select folder.

You will still need to change the game installation folder I mentioned above though for future games to be installed there.

When I downloaded the games all I got were two exe files, one for each game. I downloaded the files to my D: drive in users\my name\ GOG Games. My problem is that when I execute one of those files it goes on line and downloads a installer. I do not get a choice as to where that installer is downloaded to.

In your library, don't click the big "Download and Install Now" button - this will only download an installer for the GOG Galaxy client. You can of course use Galaxy to install games (and there you can also specify where the games should be installed), but if you don't want to, look below the blue button where it says "Download Offline Backup Game Installers". Click on that and download all files that are displayed. These are the actual game installers, and you can choose where you want the games installed, and you also don't need Galaxy that way.

This is what I was looking for, I appreciate your answer.

I have never used a program as completely FUBARed as that Galaxy. I have at least 2 FO3s installed on my machine now as that pos Galaxy does not seem to know that you have the game installed if it is not in the first place it looks. Consequently if you launch the game from the desktop icon to change your settings it wants to install the game again.

I will have to delete and uninstall everything and start all over again.

wait until you see Galaxy 2 mate :[