Need help to install two Arduino IDEs side-by-side

I have installed Arduino IDE 1.6.5 and installed the TeensyDuino libraries on top of it to support the Teensy 3.2 hardware with its Ethernet adapter.

Now, I need to work with an M-Duino which uses a different Ethernet library. I want to install 1.6.10 for the M-Duino, but I need to keep the 1.6.5 for the TeensyDuino development.

I cannot seem to have both IDE versions installed at the same time. When I try to run the 1.6.10 installer, it tells me "Arduino version 1.6.5-r5 is already installed and must be uninstalled before you can install this version."

How can I get a clean install of an Arduino IDE that will coexist peacefully with an older, customized version of the IDE?

Don't use the installer. I'm assuming you're using Windows. If so you want the "ZIP file for non admin install" download. Then you can have as many IDE versions as you like installed.

Pert's method is my PREFERRED one as I currently use 1.6.5, 1.6.9, 1.6.11, and an hourly build.

In my case the same preferences file is picked up by all four IDE's which I also find beneficial for the MKR boards

I only have 1.6.5 actually INSTALLED per se.

You can have multiple IDE's indeed. But why do you need them here? What has changed between 1.6.5 and 1.6.10 that makes you want to use both?

@ septillion

In my case ESP8266's were an issue in some IDE's that's why I kept 1.6.5.
1.6.9 was a very stable release and great for the MKR1000 boards and 1.6.11 is presently a preferred dev IDE for CREATE / MKR

Macs OS's have issues with IDE's too so some older macs cannot always use the latest or in some cases the most current stable IDE

Different strokes for different folks...

Okay, clear. I have no idea about all the MKR stuff so I'll believe you. I still run 1.6.4 because I found that a stable version. In my experience 1.6.5 up to 1.6.9 where not stable at all :stuck_out_tongue:

What I thought was you might wanted different library folders as well but that's not the case.