That menu is something completely different; "identify browser as" rules how (as what browser) the browser should identify itself when in connection with the
web server, not.. in your local environment.. (Makes sense?)
To set a browser as default on your computer, I would download
SetBrowser -->
http://www.pc-tools.net/win32/freeware/setbrowser/
Also, search this forum for "default browser" for more info.
/Hugo