If you think there's a chance that you'll be multi-booting or adding Recovery Console to your system disk (in which case you'll need to use the startup menu instead of disabling it), you might want to edit the boot.ini file instead of doing what joinT has suggested. In that case you would need to make a current Emergency Recovery Disk, in case something goes wrong with this procedure. Then go to go to the View tab of the Folder Options dialog in Windows Explorer (on the Tools menu). You would need to check "Show hidden files and folders", uncheck "Hide file extensions for known file types", and uncheck "Hide protected operating system files (Recommended)". Then hit the OK button. This will enable you to see boot.ini (in the root of drive C🙂. Select the file, right-click on it, select Properties from the context menu, uncheck Read-only. Now open the file in a text editor. Notepad will do if you're careful with it. You should see some lines that look familiar here. (BTW, you can adjust the timeout value from here, just as you can from within the System Properties dialog. You can still set it to zero, in System Properties or by changing the number here to 0. You don't really need a boot menu as long as there are no choices in it!) Assuming that the W2K installation's location information is given in the line that begins with "default=", you should be able to simply remove the lines containing the NT4 information. Leave any line referencing Windows 2000 alone. BEWARE: Delete a full line at a time ONLY, being careful to leave the rest of the file and its format intact! Now quit the editor, choosing to save the changes. Use the file's Properties dialog to reassign the Read-only attribute. Now go back to the Tools menu in Windows Explorer, and change those settings back -- unless you like them set this way. Do be very careful, however, not to just fiddle with critical system files because you can now see them in Windows Explorer.
If W2K is NOT your default, then you should probably post the exact contents of your boot.ini here so you can be guided about what exact changes to make to it. It ain't rocket science. Actually, that's the problem. The mistakes you can make with this file that will whack you have to do with the fact that it's so damned simple and innocent-looking!
Now when you reboot, you should see the boot menu with just the W2K choice, or you should see no boot menu if you set the timeout value to 0. The point is that, if and when you add another OS or the Recovery Console to the system, your menu will be useful again -- as soon as you change the timeout value to something greater than 0.
If you don't plan to add another OS or the Recovery Console, don't worry about it. I just thought I'd mention this because I'm a firm believer in the Recovery Console.
Regards,
Jim