A few things to note before starting...[]
1.) You will need the switch.bat file which can be downloaded here!
2.) Switching from one private server to another only requires step 1 through 4. If you're switching between retail and Eden and you had retail installed before Eden, you'll need to follow steps 1 through 5.
3.) Your other installation will be referred to as "OtherInstall", while Eden will simply be referred to as "Eden"!
How to run two installs[]
1.) Install Eden using the installer. This can be found in the #install-support-links channel in the Eden discord! Choose an installation location other than where your OtherInstall is located!
2.) Download the .bat file linked above and place one copy of it in your OtherInstall location, and one copy of it in your Eden install location. This should be in the \PlayOnline\SquareEnix\ folder for each install.
3.) If you want to play on Eden, simply run the .bat (As an administrator!) in your Eden installation location. If you want to play on the other server, run the .bat in the OtherInstall location (Still as an administrator!)
4.) Make sure to re-target which loader you want by editting the profile that you use. Click the red button with the 3 white dots to the right of the "File:" line and navigate to where the loader is for OtherInstall.
Make sure to select "All Files" to the right of "File Name::" so you can see the loader.
Unless your OtherInstall is a retail installation, you do not need to do step 5!
5.) If you installed retail before using the Eden Installer, once you switch BACK to retail you'll have to update via Retail's PlayOnline. This will only happen once! From then on you'll be able to switch back and forth as per usual.