Please try these instructions to install via the command line -ms [https://wiki.mozilla.org/Installer:Command_Line_Arguments] If you prefer an .msi installer, a company called FrontMotion create .msi installers for Firefox - [http://www.frontmotion.com/Firefox/download_firefox.htm] If you would like to build it yourself, [https://developer.mozilla.org/en-US/docs/Developer_Guide/Build_Instructions/Windows_Prerequisites these are windows prerequisites] I hope this helps!