make a floppy from the W98SE OEM file at www.bootdisk.com and boot from that.
If you have ME, W2K or XP you can't without that floppy.
Only W95 and W98 can, because they still include DOS.
reboot in DOS.... as in rebooting the comp? (crt+alt+del) << twice should reboot any computer in windows platform. never used others except for apple2E and that was the same also.
As ru_ready almost said. There is no need for any "shutdown" sequence in DOS (unless you have set up some advanced disk caching software). Just exit whatever program you are using and press ctrl+alt+del/reset/powerbutton when at the DOS prompt.