Long story short, my Fallout 4 XBox is bricked beyond repair because of the next gen update and i'm looking to buy the GOG version to recreate my console character and continue his wanderings there. Being able to prevent the next gen patch of causing a mess is a nice boon too.

I thought i had everything covered about the fact that both version share the same INI and save location and how to make a shortcut for Fallout4.exe to avoid using the launcher because that would start Fallot 4 Steam instead. I was also planning to use Wrye Bash to manage my mods.

But then i realized that both games also share the same plugin.txt and i see no way to get around that problem.

Could someone be kind enough to give me some tips on how to solve this so i can still get both Fallout 4 Steam and Fallout 4 GOG?

So after doing some research i found out i can have different INI and save locations if i use MO2 for Fallout 4 GOG.

I've never used that tool.

Can someone help me by explaining how to install Fallout 4 GOG through MO2 without damaging my Fallout 4 Steam installation?

Try using Bethini. You don't need MO2.

I don't know how extensively you have modified the official games with third-party mods and whatnot. I do know one thing: multiple installations of either Fallout 3 or Fallout 4 or both can coexist on a single computer. They all use/share the same location for customization data and save files, which is nice, unless you modify their default configurations.

I know this because this enables the option to install the games on a today's fastest external hard drive (with up to 2TB/s read/write speed, significantly faster than most internal hard drives) and then use that as a dedicated gaming hard drive for playing the same games on different computers, such as a travel laptop. Benefits: 1. take advantage of that expensive drive's super fast speed; 2. avoid having to download/install/update/patch/sync the same games whenever switching computers.

You can do this too. Steam and GOG will create two separate installations by default. You can optionally have them create more installations as well, such as a 3rd one on a travel hard drive such that your laptop computer with insufficient disk space can also run these games. It's up to you.

I had both installed at the same time. In fact, they worked more or less "seamlessly" together, as they shared settings and saves. I had been on Steam for years, but was in the middle of a game and didn't want to update on April 25 when the next gen update was released and experience the new content in an already existing game. However, Steam wouldn't allow me to play after that date without updating (my normal green PLAY button transformed into a blue UPDATE button.

So, I installed the gog version, double clicked the desktop icon, and boom, it continued on as if I were still playing the Steam version. Same settings, and just had to hit Continue in game and it continued on with my current game without moving files or changing settings.

I play perma death on survival and have since died in that game and reverted back to Steam with the new content from the next gen update. NOTE: Your first few minutes out of the vault are jarring with the next gen update. Something like six or seven quests come up one after the other after other. It's almost a little immersion breaking, but I guess that was the easiest way for them to add the new content by just having it start right at the beginning (unlike the other add on quests that trigger at certain levels... like automatron I think is level 15, and Nukaworld is either level 20 or 30.

But yeah, you can have both installed at the same time.

For both Fallout 3 or Fallout 4, all the installed add-ons (i.e. DLCs) are activated once you have completed the tutorial of the game and exited the initial vault for the first time. In this regard, both games are the same.

However, 1) Automatron (Fallout 4 add-on) has a level restriction - therefore, its quest line is 100% dormant until you have reached that level, which is indeed 15. This restriction is understandable, as the base game will be significantly different once this DLC has been actually started (Note: you don't have to start it at level 15). From this moment on, robots will replace raiders and start to show up in many places, and compared to raiders, many of the robots are virtually unkillable to a level 1 character.

2) Broken Steel (Fallout 3 add-on) has a special plot requirement prior to starting its quest line - therefore, its quest line cannot be started until you have completed the main quest line of the base game - and that must also be done in a certain way in order to trigger the Broken Steel quest line. However, Broken Steel brings tons of changes to the base game - the entire game is modified with this add-on - all such changes are activated upon the player leaving Vault 101 for the first time.

3) Nuka World (Fallout 4 add-on) only has a level recommendation, which is 30 - therefore, you can (attempt to) travel to the Nuka World at level 1. Your level 1 character may have to die many times in order to complete this journey. However, by using the save/reload system wisely, every time your character dies, you gain a permanent foothold inches further on your journey to the Nuka town. By using up everything the games offers you during this journey, you can - sooner or later - no matter how many times you die - complete this journey - even if you are still level 1 upon exiting to the streets of the Nuka town. This is just how this DLC is designed. If you don't want to die, wait until level 30+. Otherwise, start it as early as you like - even at level 1.

The gunner commander that you must kill prior to traveling to the Nuka town serves as a test. The game offers this test to let you decide how ready you are for the journey. For a level 1 character, that commander alone (level 38+) is a tough nut to crack.

In the entire universe of Fallout 4, you only get two named gunner commanders (there is a 3rd one of rank commander, but is called Corporal Torin instead). One of them is this woman. However, use some wits, reload and repeat, you can eventually kill her even with a level 1 character. Again, this's just how the DLC is designed.

Nothing is "Impossible"
You can set up as many installs as you want, it's mostly just careful preperation & planning.
Ultimately, with that planning ahead, it's reduced to a maximum of two simple renaming tasks.

Difficult only if you can't RTFM, even then there's a TLDR minimum info section, but there are some hidden Gotchas.

It's perfectly possible to have multiple GOG & Steam installs.
To workaround Steam, the old school ways ALWAYS work, there are many other ways these days, this is the "If all else fails" method.
Steam Demands the Game folder is "Fallout 4", your have "not in use NOW" Names "Fallout 4 NG" "F4 LG", anything except "Fallout 4"

Emulating Steam is also an option (Not piracy unless you use cracks as well), but I'm not skilled enough yet to give advicce.
I'm looking into ways to get a working CK on GOG, ideally without cracking the CK DRM. (But I will if I must).
First you MUST use MO2, dedicated saves & Ini's

You set up each Game separately

I'll give my current "get CK working with latest GOG release test setuo" (Note: I bought F4+DLC on Steam At release & got SSE free due to buying Skyrim + DLC from a reseller, before I even installed Steam (Noob user mistake) in 2012, to mod the game.

I was dealing with "Dev Patch" broke my mods, constantly as part of MO support & at that time I knew more than Tannin about Using MO to actually mod games (Tannin never modded the games)
The most knowledgeable BGS reverse engineering coders rarely play, or mod the game, it's most likely why they ARE so good at modding the games undocumented code..
Tannin was working full time & skilled users like me were his User support, so he could use the limited time he had makingg MO better to use, implementing (Or NOT) the features we needed.

My extreme allergic reaction to ANY "In-Game Cash Shops" forced me to remove both F4 & SSE from my Steam Account in 2017.
I have bought the games AGAIN on GOG, and removed them ALL from Steam, because BGS can't add the cash shop on GOG.

For me removing Store Clients is more important than even removing DRM, GOG just does both, which is great.
I'd be OK with offline DRM if other Stores let me dump their useless POS Client, like I do the useless POS called GOG Galaxy.

So given I don't technically own the Steam Games now, I'm not needing to do the Steam renaming go round at all.
What I am clued up on though, due to my highly modified setup, is getting things working when "They" say you can't.

It is usually a matter of getting stuck in & keep breaking things, trial & error until it "Just Works".
MO2 is quite forgiving of user error, so DON'T PANIC if MO2 opens & shows you an empty Data folder (Just Vanilla, or nothing at all.
Shut MO2 Down.

I have three GAME installs GOG + LG + NG
E:\Games\Fallout 4 GOG
E:\Games\Fallout 4 LG
E:\Games\Fallout 4 NG

One Global MO2 install, I actually have two but they act on the same Game Instances, because I actually use Mod Linked edition.
Note I do NOT follow the Mod Linked Collection, but I really like the Tweaks that it adds to MO2, Plus I use many MO2 Plugins.
The Root Plugin (gives MO2 Game folder control), & others I consider must haves, but Not
MO2 – Mod Organizer 2
E:\Managers\MO\MO2
MO2 – Mod Organizer 2 – ModLinked Edition
E:\Managers\MO\MO2ML

I only mention it to show that you can do that, to try a new version out alongside the old.
Also as I'm only on GOG now, this is a "Barebones Setup", my Utilities Folder will get much bigger,
I had nothing when Fallout: London released,
All 3rd Party tools (may need additional steps, making sure their settings sync correctly with MO2's VFS Data folder, not the actual game folder, though typically that DOES NOT mean (saves & Ini) locations in MO2 Profiles.
It can work changing them, but it's a workaround, not the correct method.
E:\Managers\MO\Utilities\
E:\Managers\MO\Utilities\A Collection Of MO2 Utilities
E:\Managers\MO\Utilities\BA2 Archive Version Patcher
E:\Managers\MO\Utilities\Bethini Pie
E:\Managers\MO\Utilities\BetterWabbajack
E:\Managers\MO\Utilities\BSAOpt
E:\Managers\MO\Utilities\BSArchPro
E:\Managers\MO\Utilities\Cathedral Assets Optimizer
E:\Managers\MO\Utilities\CLASSIC
E:\Managers\MO\Utilities\HUD Framework - Auto Patcher
E:\Managers\MO\Utilities\Kezyma’s Setup Tool For MO
E:\Managers\MO\Utilities\LOOT
E:\Managers\MO\Utilities\Resaver
E:\Managers\MO\Utilities\Vault-Tec Enhanced FaceGen System
E:\Managers\MO\Utilities\Wrye Bash
E:\Managers\MO\Utilities\xEdit
E:\Managers\MO\Utilities\xLODGen
E:\Managers\MO\Utilities\zEdit

Each game gets it's own Global Intance Location
E:\Managers\MO\Games\F4 GOG
E:\Managers\MO\Games\F4 LG
E:\Managers\MO\Games\F4 NG

We have an extra folder that is NOT a global instance, it's a SHARED MODS FOLDER for all three instances.
E:\Managers\MO\Games\F4\Mods

Where we have version specific Mods (Mainly F4SE plugins), & newer version agnostic variants are the latest trend.
I've barely been around a month & quite a few GOG plugins have been replaced by universal ones.

Regardless, I make extensive use of my three Suffixes in Names, & always make sure the version MO lists is correct.
FoMod version NOT contents, authors not following Versioning standards, mean the Nexus reported version may be wrong.
Mods from LoversLab & other sites you MUST add the URL manually, and I make the NexusID -1, NOT 0.
Not sure if it's actually matters now, the negative number stopped the page lookup quicker in MO.

Profiles Nothing much to see here UNLESS you have existing Profiles you want to adapt.
Copy the ENTIRE Profile folder
E:\Managers\MO\Games\F4 GOG\Profiles
E:\Managers\MO\Games\F4 LG\Profiles
E:\Managers\MO\Games\F4 NG\Profiles

Known Gotchas
For the games there are two things that need manual editing (Which can always be automated using batch scripting).
I'm NOT writing scripts, I just do it manually,
Steam Folder Rename
Registry Location of the current game*

*This messes up 3rd party TOOLS mostly, game still runs without it
xEdit & LOOT need this set correctly.
F4SE does NOT need it set, but F4SE plugins might locate the game, the LooksMenu Presets need this set Here's an example "Fallout 4 LG.reg" File content, if you're not comfortable editing the Registry directly, which is what I do.
This file would be what is used in a batch script, to make it a one click & done with the Steam Folder name shuffle.
A power Shell script could do it without the files, but it's just two renames, so DIY is easy enough.

F4SE GOG Argument (Worked for Fallout London, it should never be required for GOG)
-ForceSteamLoader

This doesn't run Steam, using the GOG release, but is a good example of finding out what works.
Maybe the Setting got baked into the launch build, made on Steam, which did provide a built in SkSe.
It's a good reminder that sometimes a weird setting "Just Works", that shouldn't, because it got baked into the compile.

TLDR
Remember, if it goes wrong DON'T PANIC, take note of what you see, then Shut Down MO2
For new setup use MO2 to create the Instances
Transferring existing setups is best done manually & Carefully (
Took me several attempts to iron out the SNAFUs

MO2 shows No Data folder content not even BGS files, Registry setting is WRONG.
MO2 only shows Vanilla content, Mods Folder pathing Wrong
MO2 Good, LOOT Shows Nothing, Or Just Vanilla, You need to set up EACH Game in LOOT as a Seprate Instance.
Loot matches MO2 in this regard & you need to make sure they Sync
Inside ModOganizer.ini "mod_directory", NOT "Mods_directory"

MO2
E:\Managers\MO\MO2

For Steam users the CURRENT Game MUST ALWAYS be renamed to "Fallout 4", their can ONLY be one.
Plus Registry location must ALWAYS match the CURRENT game (this one applies to GOG & Steam)
[HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\Bethesda Softworks\Fallout4]
"Installed Path"="E:\\Games\\Fallout 4 LG\\"

Three GAME installs
E:\Games\F4 GOG
E:\Games\F4 LG
E:\Games\F4 NG
Use the same MODS folder & DOWNLOADS Folder for all three instances (YOUR current MO Installs "Mods"
Every mod you ever is ntalled for Fallout 4
E:\Managers\MO\Games\F4\Mods
K:/ModArchives/MO/F4

We then move to the App Data content that can't be moved.
%LocalAppData%\ModOrganizer\Fallout 4 GOG
%LocalAppData%\ModOrganizer\Fallout 4 LG
%LocalAppData%\ModOrganizer\Fallout 4 NG

Files to be copied to each instance.
Categories.dat
NexusCatMap.dat

Here I ONLY show the Required Edits, mostly they are identical.
%LocalAppData%\ModOrganizer\Fallout 4 GOG\ModOrganizer.ini %LocalAppData%\ModOrganizer\Fallout 4 LG\ModOrganizer.ini %LocalAppData%\ModOrganizer\Fallout 4 NG\ModOrganizer.ini With each Profile you need to Scroll down to
[customExecutables]

The game Folder will need replacing in every path, for example My original GOG install was
E:/Games/Fallout - Series - Game 8 - Fallout 4 - Game Of The Year Edition (GOG)
For each Instance, I used Notepad++ Replace Function to rename all to fix that, if not certain you can do that safely, you can step through the process, using just rename & It will move to the next one, then wait for you to press Rename, or Find Next.

So every one of those needs changing to mach that Instances new Game Folder.
Also Note "Game Name" is "Fallout 4", regardless, & LOOT has a similar Source Game Name Gotcha, Fallou4.

Text files for settings are a modders best friend, if we can edit the bugger, we can fix the bugger ourselves.

Above all DON'T PANIC, opening MO2 changes nothing, closing MO2 changes nothing.
Panic & try & fix your mistakes WITH MO2 does SOMETHING.
Whether it Fixes your error, or not, depends on what your mistake was.

As long as you do nothing MO2, does nothing & you can always MAKE A BACKUP before you start editing, get one insrtall right first & the others are easy.

All you need is to get into the Switching Instance habit,
RENAME Steam Folder
RESET Registry Path

Have Fun.

Just to add the MO auto generated files in the Profile you made the mistakeb inside can give you a fright when you see an A To Z Mod Priority, in a 1000 mod Priority list.
DON'T PANIC
You have made a Backup?
Even if you didn't, (You actually did) we have oriigial copies in the other two profiles, we never edited those.
Simply delete the entire Profile Folder, copy a good one in fix the Ini edit, & try again.

As long as you have a Profile copy, you can restore that exact profile layout to Any MO2 Instance.

That's crazy.

Would never spend all my time doing that to play multiple copies of the same game.

To keep my old modded FO4 GOG install, while playing a clean version for Fallout London, I just renamed directories and did a new install.

I just change the directory names to whichever version I want to play. Takes like one minute and I'm not switching often. If I did it more often, I could just have a batch file to change the directory names, so it would take a second instead of a minute.

I'm done London until a major patch, so I'm flipped back to my regular install again.

Hopefully renaming directories will work for you, but this is not my experience, at least with skyrim, FO3 and FONV and total conversion mods like FO New California or the skyrim coop mod (Open Tamriel?). I did the directory backup thing to save heavily modded installs, and they all ended up broken when I tried swapping directories (multiple folders on C:\User\*.* as I'm sure you know, some buried...)

Not saying wht you do will not work, just not my past experience with BGS games.

I've already switched back and forth a few times. It works as expected.

Of course I'm only using GoG, and further I'm using offline installers so no Steam or Galaxy trying to be smart, but actually interfering.

I also only used Vortex on my modded FO4 install, where my London install didn't use a Mod manager.

I can' think of any reason why switching back and forth wouldn't work in these circumstances and indeed, it does work just as expected.

You just have to get all the directories. For most games, that's 2 top level directories, but for FO4 it's these three, in there current state of FOLON in backup mode, I used _Original to backup the normal game...

C:\Users\YourName\AppData\Local\Fallout4_London

D:\Games\Fallout 4 GOTY_London

C:\Users\YourName\Documents\My Games\Fallout4_London