Hello, You can check this SUMO article [[Install an older version of Firefox]]. The location for the Firefox 22.0 installer is on the public FTP [https://ftp.mozilla.org/pub/mozilla.org/firefox/releases/22.0/win32/en-US/Firefox%20Setup%2022.0.exe Firefox 22.0 installer] Hope this helps.

Firefox 27.0 is in Beta at moment until February 4 release. You would be better off trying to use wither the User Agent Switcher extension or ua-site-switch extension to try a fool this one site or to use the portable Firefox 22.0 just for this one site. https://addons.mozilla.org/en-US/firefox/addon/user-agent-switcher/ https://addons.mozilla.org/en-US/firefox/addon/ua-site-switch/ You should not switch to using 22.0 only due to known potential vulnerabilities that is fixed in newer versions like the current Fx 26.0. The Portable Firefox is a self contained program as it will not interfere with your current Firefox 26.0 install. It can even be used completely on a usb flash drive. http://sourceforge.net/projects/portableapps/files/Mozilla%20Firefox%2C%20Portable%20Ed./Mozilla%20Firefox%2C%20Portable%20Edition%2022.0/ and pick your language. I posted a ink to portable Firefox 22.0 as their homepage currently only links to the current 26.0 and 24.2.0esr on http://portableapps.com/apps/internet/firefox_portable