Ultramon, 453-454
unneeded items, deleting, 429-430
uninterruptible power supply (UPS), 295-300
Unix operating system
finding drivers for, 538-539
overview, 534-536
Windows services for, 540
updates for Windows, 406-409
upgrading
desktop computers, 7-8
laptop computers, 328-329
UPS (uninterruptible power supply), 295-300
USB
connecting to Windows computer, 253
connectors and cables, 250-253
data transfer
bulk transfers, 248
interrupt transfers, 247
isochronous transfers, 247
enumeration, 246-247
hubs and expansion cards, 245-246
overview, 244-245
power distribution, 246
USB drives
connecting, 152-153
external USB disk drives, 153-154
on laptops, 328
overview, 362
USB keyboards, 196
USB mice, 218
USB ports, 325, 558
USB2, 675-677
user interface, 87