Never heard of this one but seems to be a very practical way to get your PC up to date (especially when reinstalling) for those of you stuck with Win98... spotted at Neowin[]:

Microsoft has never released a service pack for Windows98 SE. 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.