files belonging to other users using a special private key. By default, local administrators are recovery agents however they can be customized using Group Policy. Basic and dynamic disk storage Windows 2000 introduced the Logical Disk Manager and the diskpart command line tool for dynamic storage. All versions of Windows 2000 support three types of dynamic disk volumes (along with basic disks): simple volumes, spanned volumes and striped volumes: Simple volume, a volume with disk space from one disk. Spanned volumes, where up to 32 disks show up as one, increasing it in size but not enhancing performance. When one disk fails, the array is destroyed. Some data may be recoverable. This corresponds to JBOD and not to RAID-1. Striped volumes, also known as RAID-0, store all their data across several disks in stripes. This allows better performance because disk reads and writes are balanced across multiple disks. Like spanned volumes, when one disk in the array fails, the entire array is destroyed (some data may be recoverable). In addition to these disk volumes, Windows 2000 Server, Windows 2000 Advanced Server, and Windows 2000 Datacenter Server support mirrored volumes and striped volumes with parity: Mirrored volumes, also known as RAID-1, store identical copies of their data on 2 or more identical disks (mirrored). This allows for fault tolerance; in the event one disk fails, the other disk(s) can keep the server operational until the server can be shut down for replacement of the failed disk. Striped volumes with parity, also known as RAID-5, functions similar to striped volumes/RAID-0, except "parity data" is written out across each of the disks in addition to the data. This allows the data to be "rebuilt" in the event a disk in the array needs replacement. Accessibility With Windows 2000, Microsoft introduced the Windows 9x accessibility features for people with visual and auditory impairments and other disabilities into the NT-line of operating systems. These included: StickyKeys: makes modifier keys (ALT, CTRL and SHIFT) become "sticky": a user can press the modifier key, and then release it before pressing the combination key. (Activated by pressing Shift five times quickly.) FilterKeys: a group of keyboard-related features for people with typing issues, including: Slow Keys: Ignore any keystroke not held down for a certain period. Bounce Keys: Ignore repeated keystrokes pressed in quick succession. Repeat Keys: lets users slow down the rate at which keys are repeated via