When a major version of Minecraft is released, it takes a while before mods are updated to work with it. It can happen that you want to install the new version, but keep a copy of the old version with mods installed.
Windows version keeps data in
%appdata%/.minecraftregardless of the executable’s version. Is it possible to keep two versions of Minecraft installed at the same time, without conflicts?
Answer
Minecraft puts the data in %AppData%, so you can just make batch files which set %AppData% to some other location before running the game.
This is a trivial but flexible working example:
@echo off
set LAUNCHER=c:\games\minecraft\minecraft.exe
set SUPPLEMENT=.minecraft-supplemental
set APPDATA=%APPDATA%\%SUPPLEMENT%
%LAUNCHER%
This will make that launch of Minecraft keep and look for its data (including your saves and even mods) in %AppData%\.minecraft-supplemental\.minecraft\. (The extra level of folder structure is unnecessary but harmless, and it would be hard to eliminate it without breaking the sorts of things that the %AppData% convention was designed to avoid breaking.)
Note that this will keep everything separate — remembered login, achievements, saves, Minecraft version, mods — everything. As a bonus, this not only means that you can keep different versions of Minecraft installed, you can segregate different login names into their own installs with their own saves, useful for sharing a computer with other Minecraft players.
You can make multiple versions of that batch file and change the %SUPPLEMENT% variable to keep the copies’ data separate. (Yes, it’s currently set to a dumb name. Customize it to taste. I suggest .minecraft-[username].) You can even use different Minecraft launchers by changing the %LAUNCHER% variable, allowing different versions (or users) to use different launchers.
Attribution
Source : Link , Question Author : Joe Dovahkiin , Answer Author : SevenSidedDie
