Did you type // and not \\ ? \\ does expand to file:/// for me, trying to open a network share. But // to file:/// never happened to me.

BTW, actually it seems that if I type `//foo` and `http://foo/` can't be resolved by DNS server/hosts file, Firefox does Google search, while Chrome tells that 'webpage is not available'.

Note also that some browsers want to fix http://foo to http://www.foo.com - for Firefox, see [1] and [2]

[1] about:config?filter=browser.fixup

[2] http://kb.mozillazine.org/Firefox_:_FAQs_:_About:config_Entr...