Hi,
mOrphine. You may wish to alter the way you accomplish these jobs just a bit in W2K. Let me explain why.
CHKDSK (There is no Scandisk in W2K.) will only run at boot time on the active OS partition (whichever one you're booted on). So, right there, you've got a situation where you open a command prompt, and type "chkdsk /r". CHKDSK will tell you that it can't get exclusive access to the drive (because, after all, the OS and its services are running), and it will ask you if it's okay to run the next time you boot. You tell it yes, and then it'll do its thing the next time the system boots.
AFAIK, the built-in defragger can't actually be scheduled to run automatically using the W2K scheduler without using a workaround. I know the workaround is out there somewhere, but I don't know where. I never bothered to pay attention because I use a third party defragger: Executive Software's Diskeeper on servers and O&O Defrag Pro on notebooks.
A NAV or other anti-virus scan on the system can be run on a schedule either using its own built-in scheduler or the Windows 2000 scheduler.
If your defragger is operable by issuing commands at a command prompt, and if your third party defragger is similarly operable from the command line, then you can use a script to run them manually (or you can schedule the script).
Even chkdsk can be run by script, so you could combine all three functions in a script (which is like a batch file) provided that the executables you're using meet at least the requirements I gave above.
You'd have to investigate scripting and the "AT", "NOW" and "SOON" commands, or something along those lines, to do exactly what you're talking about. It's a bit more complex than a batch file. And possibly not worth it since you can accomplish the same thing using the GUI tools available to you. Just requires a slight change in the way you do things. BTW, unless your drive is really small, I wouldn't count on all three of those operations being done by the time you get back from lunch -- unless you get some really nice lunch breaks!
Regards,
Jim