From KernelEx Wiki
Screenshot of Firefox 3.6
Mozilla Firefox is a free and open source popular web browser descended from the Mozilla Application Suite and managed by Mozilla Corporation. As of September 2010, Firefox was the second most widely used browser. The last version officially supported on Windows 98/ME is 126.96.36.199 (18.December.2008). With KernelEX you can install and run higher versions.
Installation and running
Firefox 10.0 esr: Installs and runs unmodified. Compatible with the Adblock extension and Flash 10.3.183.18 plugin. Installing Firefox 10.0.12esr (03.Jan.2013) avoids frequent automatic updates that can fail under KernelEx. (KernelEx 4.5.2 required)
Firefox 3.0 - 3.6.28: No special steps required. Runs out of the box. Set to Windows XP Mode.
Firefox 4.0 - 9.0.1 (KernelEx 4.5.2 required).
Notice: Recently visited addresses, history and bookmarks don't work. For using bookmarks it's possible to install the add-on PlainOldFavorites latest version 1.2.1 (now compatible with Firefox 5-9). Restart Firefox twice and allow the installation of the add-on. There is another add-on HyperBK with bookmark functionality and history. You have the possibility to hide the Firefox bookmarks menu.
Fixed with KernelEx 4.5.2: Firefox 4+ : Freeze when drawing a non-blank page.
Can't set as system browser
You can't set Firefox as default system browser. Dialog box "Would you like to set Firefox as default browser?" appears every time you start it.
Cause: Windows 9x shell does not support per-user file associations.
Workaround: Run the helper.exe with /SetAsDefaultAppGlobal parameter, as shown in example:
"C:\Program Files\Mozilla Firefox\uninstall\helper.exe" /SetAsDefaultAppGlobal
Printing doesn't work
You can't print from Firefox. Print Preview dialog may work fine, but printing will fail:
- only some parts or blank page may be printed
- program may hang or crash
Cause: Firefox Cairo printing system uses 32-bit coordinate system and printing extensions which are not supported by Windows 9x.
1. Use IETab/IEView add-ons which may allow printing via IE engine.
A promising workaround to print with Firefox 3 and newer on MSFN Printing with KernelEX. More probably it will not work, but you can check it out.
How to: Paste the downloaded ComDlgEx.dll in
a. <system> folder (for multiple apps)
b. app folder (for single or portable app)
Drag and Drop the Firefox.exe (also portable is possible) on the ImportPatcher.exe. Click no. In the first step the ImportPatcher generates two files (ini and log - marked with #) in the program folder. Open the ini file with the editor (NotePad) and paste COMDLG32.DLL=ComDlgEx.dll under [DLL replacements] and save it. After that (second step) press the retry button of the ImportPatcher. Then you cancel the ImportPatcher.
If this doesn't work, delete the log and ini file and do it again, but click yes (walk dependencies) in the first step.
Explanation: A *#.* copy of every file that is walked is created, including system DLLs. If you run into trouble please post it on the MSFN topic Printing with KernelEX.
Changing system settings stalls while Firefox is running
When you try to change appearance theme in Display Properties, or in RPConfig with Revolutions Pack installed, or changing other system settings which are propagated to other apps, Firefox doesn't respond to changed settings. Other apps may hang when you apply settings until Firefox is closed with Ctrl-Alt-Delete.
Cause: There's a bug in Windows 98 message broadcasting.
Solution: Update USER.EXE and USER32.DLL to version 4.90.3000 or newer.
JRE doesn't work with recent releases
Java classic works up to version 3.5.19. There is no known workaround to run Java applets in Firefox 3.6 and higher on Win ME/98.
Firefox is starting in offline mode
The problem doesn't occur with Firefox portable.
network.manage-offline-statusto false (usually you have to create this entry as a Boolean).
Firefox runs slow - versions 4 and higher
Try disable "Use hardware acceleration when available" (Tools > Options > Advanced > General). Run it with compatibility mode "Default mode".
Firefox 3.6 is recommended because it is the most stable and reliable release for KernelEx systems.
If Firefox 10 hangs or freezes while idle, then disable background update checks:
1. Click Tools -> Options -> Advanced.
2. In the General tab, disable Submit crash reports and Submit performance data.
3. In the Update tab, disable Automatically install updates.
Note there are reports that Firefox 10 runs on some ME/98 systems, but also reports of other people that it hangs or crashes, regardless of the above-mentioned settings.
Firefox 11 installs and runs unmodified on KernelEx systems, but are slow and have noticeable rendering glitches.
Firefox 12 freezes after a few seconds.
Firefox versions 13 and higher cause an error in MSVCR100.dll and don't start.