From authors website:
Microsoft has never released a service pack for Windows98 SE. But I made a Service Pack for Windows98 SE users. It contains all Windows98 SE updates from Windows Update site and more.
It is a self-extracting and self-installing pack like Microsoft's update files. Thus, you cannot choice files individually. However, the pack installs only required fixes for your system. Uninstallation is possible from Add-Remove Programs.
****This is only for WINDOWS 98 SECOND EDITION ENGLISH****
I highly recommend that you should backup your system before installing the pack.
It contains only operating system updates. It does NOT contain Internet Explorer 6, DirectX 9, Media Player 9 and their updates.