>I have an old 486 running Win95. For several years we could use the Shutdown command to reboot to a dos prompt. It doesn't work anymore: you simply return to windows. If I bring up the boot menu during startup and select command prompt only, I wind up in in windows. Safe mode command prompt does get me to a C:\ prompt but i can't do anything when i get there. The only new software in the past 6 months has been Norton Anti-Virus. I disabled and then uninstalled it, and it didn't help. Anybody have any idea what might be keeping this machine from booting to dos?

Yes - someone is invoking Windows explicitly in the AUTOEXEC.BAT file. Remove the line that reads "WIN" from AUTOEXEC.BAT