When using ntfs as a file system, what can be used to control the amount of hard disk space each user on the machine can have as a maximum?

You must be administrator.

Right-click on the device, click 'Properties', then 'Quota'. Then you can:

- Enable or disable disk quotas on a volume. - Prevent users from saving new data when their disk quota is exceeded. - Set the default disk quota warning level and disk quota limit assigned to new volume users. - View disk quota information for each user from the Quota Entries view.