Windows 98, 98SE, and ME have reached the end of their support lifecycles.
Support for Windows 98, Windows 98 Second Edition, and Windows
Millennium Edition (Me) ends on July 11, 2006, which is the July 2006
Monthly Bulletin Release date. This means Microsoft will end public and
technical support on July 11, 2006. This also includes security updates.
Also, an anticipated update to Windows Explorer won't be provided, either. See the FAQ.
After extensive investigation, we’ve found that it’s not
feasible to make the extensive changes necessary to Windows Explorer on
these older versions of Windows to eliminate the vulnerability.
Windows XP SP1 will be soon reaching the end of its support lifecycle, too. Update, before it's too late.