That is not certain.<br /> Sometimes the devs enable updating from Firefox 3.6.x to the latest Firefox 5 release and sometimes you can only update to the latest Firefox 3.6.x version.<br /> Actually you can only do the latter on Mac because the Firefox 3.6.19 version for Windows and Linux doesn't add anything, so the decided not to offer that update on those platforms.<br /> Updating to Firefox 5 may be offered again in a few weeks from now, but at the moment there is no update. ---- *https://aus2.mozilla.org/update/3/Firefox/3.6.17/20110420140830/WINNT_x86-msvc/en-US/release/Windows%20NT%206.1/default/default/update.xml *https://aus2.mozilla.org/update/3/Firefox/3.6.18/20110614230723/WINNT_x86-msvc/en-US/release/Windows%20NT%206.1/default/default/update.xml *https://aus2.mozilla.org/update/3/Firefox/3.6.19/20110707195905/WINNT_x86-msvc/en-US/release/Windows%20NT%206.1/default/default/update.xml