Why does "Git help <command>" not launch html help in my browser, like it says it should?

I just recently had the same problem, browser wouldn't launch. I'm running Git 1.9.2.msysgit.0 on Windows 8.1. Default browser - Chrome.

None of the solutions above worked for me. But I simply went to the html file in the explorer, and double-clicked it. Windows then asked me what app to use to open it, and I chose chrome.

Now usual git commands work and open the help html files in Chrome.

As mentioned in the msysgit bug report 445:

Git has it's own tool called "git web--browse" that invokes the web-browser.

Set the environment GIT_TRACE to 1 to see what processes are started, and with what command-lines.

So that can help debugging the issue.

A temporary workaround (which might not be effective in your case) was:

As temporary workaround one can rename all git-<command>.html to git<command>.html in his <Git>\doc\git\html directory.

The git <cmd> --help suggested by Andy seems to have helped though, and must have "reset" something.