It's not practical to do this, as far as I know.
If you have identical workstations throughout your organization, you are far better off having a generic boot image (with all of the clients custom desktop settings, local data, files, etc.) residing on a 'home' drive mapped to the server. This offers a variety of advantages:
1. Backups are consolidated. Your home drives are all residing on protected servers. Server storage is more efficiently utilized.
2. Backups are not going to fail because a user has his/her system off.
3. The performance of your network, and your backup processes improve since you are not moving the traffic of 10,000 backup jobs across it.
4. If a user loses a drive, the 'standard' drive image can be reloaded on a new drive in short order, and when they log in, they are basically using the same system. Also, if they log in on another user's system, they are basically going to be on their 'own' system for all intents and purposes.
5. Reduced support overhead on those 10,000 systems.
If your environment has variety of desktop systems and OS's, you can still do the same thing to a certain degree, you just won't have the advantage of a 'gold' standard system's image. But user data is protected on the server, which prevents the wasted storage effect you are seeing on your 10,000 workstations.
Hope this helps,
This was first published in April 2003