Many people have had major problems with this "critical" update. Now it looks like Microsoft screwed up and Win9x doesn't need this patch at all!
http://tinyurl.com/5qv6j
"Got with a tech support guy fairly quickly (!) and he explained that the KB891711 patch was not required for WIN98, even though the Windows Update service called it a critical update. He had me uncheck it in the Startup list on msconfig, and also remove it from the registry: Run Regedit, export a registry file to the desktop as a backup, go to HKEY_LOCAL_MACHINE/Software/Microsoft/Windows/Current Version/"