Setup p4merge as diff and merge tool for git on windows
Download and install p4merge from chocolatey
Setup p4merge as git's diff and merge tool. To do this, edit your .gitconfig under c:\users\[yourusername] and add the following lines:
[merge] tool = p4merge [mergetool "p4merge"] cmd = p4merge "$BASE" "$LOCAL" "$REMOTE" "$MERGED" trustExitCode = false [diff] external = p4mergeDiff.bat [push] default = simple
Create a p4mergeDiff bat file to handle diff which only requires 2 arguments, old and new files. Put this file in your p4merge install folder: C:\Program Files\Perforce\p4mergeDiff.bat
p4merge "%2" "%5"
Now restart your powershell to ensure that all of the paths are available and do a git diff. Each changed file will open in sequence as you close the previous one.
For reference and instructions on linux, check the official documentation at : http://git-scm.com/book/en/v2/Customizing-Git-Git-Configuration