Adding "StartMenuScrollPrograms" and set the string
to "False" in the following Registry key will
enable "Multi-Column Start Menu Style" in Windows 98 SE:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\Curr entVersio
n\explorer\Advanced\Folder\

However it works only for those folders under
the "Programs" in Start Menu, it does not work for the
folders in the "Start Menu" (above "Programs"). Anyone has
a tip to enable the multi-column in Start Menu?