UART (Universal Asynchronous Receiver/Transceiver), 424, 476, 857
UDMA (Ultra Direct Memory Access) drives
mixing, with different ratings, 164
speed ratings, 132, 143
Ultra DMA, 398, 468
Ultra-wide SCSI interface, 535
UMA (Upper Memory Area), 453–454, 857
UMB (Upper Memory Blocks), 454, 857
UNATTEND.TXT, 719
UNC (Universal Naming Convention), 587
Unicore.com, 83, 84
Uninstallation of programs, 22–23
Universal Serial Bus (USB) ports and drives, 93, 94, 153–154
Updates, Windows
Service packs, 26
web address for, 57
obtaining, 57–58, 266
WINNT32 for, 330–331
Upgrades, OS. See specific operating systems
UPS (Uninterruptible power supply)
BIOS updates and, 84
importance of, 8, 10, 285
selecting and using, 64–65
UPS (Uninterruptible Power Supply), 401–402, 857
URL (Uniform Resource Locator), 596, 857
USB (Universal Serial Bus)
architecture, 411
connections, 557–558
drives and ports, 92, 94, 153–154
defined, 857
keyboard and mouse connectors, 554–555
motherboard connectors, 398, 550
mouse, 473
patch, Windows 95, 558
USB 2.0, 557–558
Usenet groups, 262
User administration
account creation and management, Windows NT, 693–694
Active Directory, Windows 2000, 734
profiles and system policies, Windows NT, 696
profiles, Windows ME, 769–771
profiles, Windows XP, 815–816
USER.DAT, 654
Utilities
Automated System Restore (XP Professional), 283
Emergency Repair Process, 278–279
Last Known Good (LKG) Configuration, 277, 691, 723
Recovery Console, 281–282
Registry repairs, 271–273
Restoration of System State Data, 282–283
Safe Mode Boot, 274, 286
System File Checker (98, 2000 and XP), 274–277
System Restore, 281
Windows 9X, reinstalling, 279–280
UTP (Unshielded Twisted Pair), 562–564, 857
UVGA (Ultra VGA), 496–497