Firefox 2.0.0.20 is the last ever version of Firefox for Win98 / SE / ME.

I understand 2.0.0.20 is the last What I am trying to undersand is how to fix the XML malformed problem

Hum, I doubt you'll get any help here. Firefox 2.0 is no longer supported. In fact, all versions prior to Firefox 3.5 have been discontinued and are no longer supported by Mozilla. On top of that, they have known unpatched bugs and security problems. Use previous bellow 3.5 with caution and please make sure you are aware of these problems.

It is true, however, that new versions of Firefox (anything above Firefox 2.0, in fact) do not work with older versions of Windows (Windows 98 included). However, I will remind you that Windows Me (in fact, any version of Windows prior to Windows XP) is no longer supported by Microsoft, and, like older versions of Firefox, has known unaddressed problems and security issues.

As such, I urge you to update your operating system. Windows XP is still widely used, will be supported until 2014, is relatively cheap and should run ok on your computer (please check its system requirements first). Older computers are normally not capable of running Windows Vista and above. If upgrading to a new version of Windows is not possible or you simply don't want to, there are many different distributions of Linux that will easily work in your computer, and easily surpass Windows 98 in terms of ease of use and software compatibility (if you use Wine - a software compatibility layer to use Windows applications). Getting and installing a Linux distribution is completely free (just like Firefox) and very easy too. I personally recommend Ubuntu, but you may want to try Xubuntu, a lightweight version of the former. See here for a complete list of all Linux distributions. If you need help getting started in the world of Linux, you can use the official support forums and take advantage of Linux's fantastic community.

Ok... Now that I've got the part where I tell you that your OS is not supported and you should update out of the way, I also have to tell you that Firefox 3.5 and above, despite being supported in newer versions of Windows and other operating systems (including, of course, Linux), are not supported in Windows 98, and is not supposed to work under it (since it was not developed with it in mind). If there is a way to make it work somehow, it will not be supported and we probably won't be able to help you in fixing any problems you might have. You can search the web for ways to installed Firefox 3.0/3.5/3.6 in Windows 98, but it probably won't be in Firefox's support forums.

Again, I will remind you that version 2.0 of Firefox has been discontinued and is no longer supported. It has known unpatched bugs and security problems, and, again, I urge you to update to the latest version of Firefox, for maximum security, stability, performance and usability. You can get it for free, as always, at getfirefox.com.

Morbus -thanks much - getfirefox.com it is

I dual boot win98se and fedora - eager to continue to do so - IE works in win98 but I have always been a loyal mozilla fan.

Dick

MOrbus - I went to getfirefox.com and look everywhere I can think and do no see where you get out of date versions. Can you give me a pointer?

See http://kb.mozillazine.org/Unsupported_operating_systems