No external power adapter required--so you can read CD-ROM, CD-R and CD-RW media in a completely mobile environment; USB connectivity also offers easy installation to desktop and notebook computers; Low power requirements - Minimal battery drain while the power is supplied by the USB port--no external power adapter required; It's super slim, lightweight, sturdy and attractive; USB Portable CD-ROM Drive is built to travel easily and maximize desk space; It connects to your computer via a USB cable. Because the USB cable also supplies power to this device, so no external power supply is required; Plug and Play, hot pluggable, and hot swappable features make this device convenient and easy to use. This item doesn't support WIN 7 OS.