Install Norton Antivirus in a dual boot

I have W98 SE installed on primary IDE as master, and W2000 Pro installed on primary IDE as slave, as a dual boot system. I installed in the proper order…W98 first. All works well…no problems. How do I install Norton Antivirus onto W98, without problems. When I install, then reboot to W2000, then reboot BACK into W98, W98 crashes and is unbootable. Has anyone done this ? (perhaps I need to install NAV on W98, before I install W2000 ?). Can I install onto W2000 also ??? Symantec says the don’t “support” NAV in a dual boot environment. PLEZ HE-E-ELP !!!
Phildo