Hello Chunix.

Although possibly not related to your problem, I will remind you that the version of Firefox you are using at the moment has been discontinued and is no longer supported. Furthermore, it has known bugs and security problems. I urge you to update to the latest version of Firefox, for maximum stability, performance, security and usability. You can get it for free, as always, at getfirefox.com.

I will also have you know that versions prior to Firefox 3.5 have been discontinued and are no longer supported by Mozilla. Furthermore, they have known bugs and security problems. Use them with caution and please make sure you are aware of these problems.

It is true, however, that new versions of Firefox (I believe anything above Firefox 2.0) do not work with older versions of Windows (Windows 98 included). However, I will remind you that Windows 98 (in fact, any version of Windows prior to Windows XP) is no longer supported by Microsoft, and, like older versions of Firefox, has known 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 the 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 software compatibility (if you use Wine - a software compatiblity layer to use Windows applications). Getting and installing Linux is completely free and is very easy too. I personally recommend Ubuntu, but you may want to try Xubuntu, a lightweight version of the former. 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, 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), is 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.

You can, however, install without any predictable issue, Firefox 2.0, which is the last Firefox release for Windows Me. To get it, you will need to access Mozilla's FTP servers. Here's a link for the 2.0 release directory:

ftp://ftp.mozilla.org/pub/firefox/releases/2.0.0.20/win32/

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

Thanks for respond.

For some reasons, I need to use Win98se. Win98se can't use Firefox newer than version 2.

I don't like to think "upgrade fix everything". Upgrade can fix something but not everything. Something can fix without upgrade. Old version have know bugs/problems, but new version also have new bugs/problems. The problem I ask should not related to bugs or security problems.

Firefox2/3 with WinXP also have slow upload problem, it can fix by registry tweak, but the registry of Win98se is different, I guess there are some similar value in Win98se registry can tweak.

Although Win98se and Firefox2 are old version, they run for long times. I know the official support is end. I just try to ask for some past experience.

Well, Firefox 2.0 really isn't supported anymore (and, as I said, neither is Windows 98), so I can't help you if you have a problem. I'm sorry.

Ultimately, it's up to you to decide whether you want to update your software. But be aware that outdate software is extremely risky to use and have very serious security issues that may and will be exploited by third parties. Browsing the web in Firefox 2.0 and Windows 98 is like swimming in a sewer. You may not get sick, but you probably will. Firefox 3.6 is much much faster, much lighter, much more stable, much more secure and much more usable than Firefox 2.0. There is absolutely no advantage in using Firefox 2.0. If you are having a problem with Firefox 3.6 that you were not having with Firefox 2.0, please ask here in these forums for support. If you want, you can use this thread, and I'll do my best to help you. I won't miss your question, since I have this thread on an e-mail subscriptions.

If you are having slow upload speeds, check your Firewall settings, and be certain that your upload speed is not slow simply because your Internet Service Provide doesn't let you upload faster.