Please download and install Firefox 12 ( the last version that will run on your computer) from ftp://ftp.mozilla.org/pub/firefox/releases/12.0/

No problem downloading Firefox 12; however, after setting it up, running FFX 12 froze at the opening screen. It was in the automatic upgrade screen and not displaying anything. I tried clicking on the Google window and also typing in a different web address, but FFX 12 was locked up. I then uninstalled FFX 12 and ran the FFX Setup 3.6.28. Am back running 3.6.28. Any other versions of FFX recommended with KernelEx 4.5.2 and Win98SE I will download, setup and run. Thanks in advance. JohnGade

Your actual version of Windows is Windows 98SE? I don't think there is a newer version of Firefox for that OS. (The advice on Firefox 12 was based on your post listing Windows 2000, so sorry about the confusion.)

I wasn't aware of KernelEx. The sourceforge page says Firefox 8 will run, but with some missing features.

http://kernelex.sourceforge.net/

Naturally, running such an old browser exposes you to a wide variety of security exploits, but I'm sure you know that...

Edit: Perhaps I should have included this link: Install an older version of Firefox.

Is there a version of Adobe Flash Player that can run with Firefox 3.6.28?

Should I try Firefox 8.0 first and then upgrade to 8.01, etc. or just try the latest in the 8 series and hope for the best? I don't know if anyone in this forum has successfully used KernelEx on a Win98SE system. If so, I hope they will jump into the conversation. JohnGade

Are you trying to run Firefox on Windows 98 (not windows 2000 as your User agent claims)? then 3.6 is the highest you can run on such an ancient operating system

... and to bring more confusion to this thread.

It is possible to run Firefox 13.0+ versions on Windows 2000.
http://forums.mozillazine.org/viewtopic.php?f=37&t=2482475

The unofficial SP5 Service Pack is here: http://windows2000.tk/

I'm on Win7 and can't update from FF20 to 21. Extraction of setup file says it is corrupt.