That seems rather unusual. Firefox 23 is outdated and would be insecure and unsafe to use outside the VPN. Companies often use a special ESR edition of Firefox that may have an older version number BUT is secure. * https://www.mozilla.org/en-US/firefox/organizations/faq/ <br /> Currently Fx 31.4.0 ---------- '''This article contains links for downloading older versions''' * [[Install an older version of Firefox]] You will need to keep your current, up-to-date, and secure Firefox release for ordinary home use, and use on the internet. You will need to install Firefox taking special steps to ensure that the two versions each have their own separate[[Profiles - Where Firefox stores your bookmarks, passwords and other user data|profiles]]. This is something done more often for the purpose of testing Firefox and the instructions are here: * http://kb.mozillazine.org/Testing_pre-release_versions#Installing_multiple_versions * http://kb.mozillazine.org/Using_multiple_profiles_-_Firefox ---------- You may wish to show this post to your IT department, as these instructions are not the easiest to follow and understand, but I am sure they will be able to help you with them. Please post back with how you get on.

IMO, you should install the [http://sourceforge.net/projects/portableapps/files/Mozilla%20Firefox,%20Portable%20Ed./Mozilla%20Firefox,%20Portable%20Edition%2023.0.1/ Firefox Portable version 23.0.1] on your hard drive. The "Portable" version won't interfere with an "official" Firefox version and will have its own Profile - avoiding potential conflicts there. Then use the "Portable" version on VPN and the official version elsewhere to take advantage of all the security fixes that have come out since Firefox 23 was new.