How do I use Notepad++ (or other) with msysgit?

git config --global core.editor "'C:/Program Files/Notepad++/notepad++.exe' -multiInst -notabbar -nosession -noPlugin"

Or, for 64-bit Windows and a 32-bit install of Notepad++:

git config --global core.editor "'C:/Program Files (x86)/Notepad++/notepad++.exe' -multiInst -notabbar -nosession -noPlugin"

Or, the following can be issued on the command line on either 32-bit or 64-bit Windows. It will pull the location of notepad++.exe from the registry and configure git to use it automatically:

FOR /F "usebackq tokens=2*" %A IN (`REG QUERY "HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\App Paths\notepad++.exe" /ve`) DO git config --global core.editor "'%B' -multiInst -notabbar -nosession -noPlugin"

If you wish to place the above from a .BAT or .CMD file, you must replace %A with %%A and %B with %%B

As of Git for Windows v2.15.0 (October 30th 2017) it is now possible to configure nano or Notepad++ as Git's default editor instead of vim.

During the installation you'll see the following screen:

I am using Windows 10 and notepad++, and I was getting this error message:

line 0: syntax error near unexpected token `(' git windows

So I make the setup in this way:

git config --global core.editor 'C:/Program\ Files\ \(x86\)/Notepad++/notepad++.exe'

and it works

I used starikovs' solution. I started with a bash window and gave the commands

cd ~
touch .bashrc

Then I found the .bashrc file in windows explorer, opened it with notepad++ and added

PATH=$PATH:"C:\Program Files (x86)\Notepad++"

so that bash knows where to find Notepad++. (Having Notepad++ in the bash PATH is a useful thing on its own!) Then I pasted his line

git config --global core.editor "notepad++.exe -multiInst"

into a bash window. I started a new bash window for a git repository to test things with the command

git rebase -i HEAD~10

and the file opened in Notepad++ as hoped.