Gtk98Icons is a GTK icon theme that looks like the unforgetable Windows 98. Most icons are ripped straight out of Windows 98. A few were created by myself. It's still pretty much a WIP.
If used in Xfce together with the Redmond GTK theme and the Redmond Xfwm theme you will end up with a desktop that looks fairly close to Windows 98, as shown here:
Install by downloading to ~/.icons
(for a system wide installation, use /usr/share/icons/)