A hard disk drive HDD, commonly referred to as a hard drive, hard disk, or fixed disk drive, is a nonvolatile storage device which stores digitally encoded data on rapidly rotating platters with magnetic surfaces. Strictly speaking, drive refers to a device distinct from its medium, such as a tape drive and its tape, or a floppy disk drive and its floppy disk. Early HDDs had removable media; however, an HDD today is typically a sealed unit except for a filtered vent hole to equalize air pressure with fixed media. HDDs introduced in as data storage for an IBM accounting computer were originally developed for use with general purpose computers.

In the st century, applications for HDDs have expanded to include digital video recorders, digital audio players, personal digital assistants, digital cameras and video game consoles. In the first mobile phones to include HDDs were introduced by Samsung and Nokia. The need for largescale, reliable storage, independent of a particular device, led to the introduction of embedded systems such as RAID arrays, network attached storage NAS systems and storage area network SAN systems that provide efficient and reliable access to large volumes of data.

The Specific Type of hardware failure can be determined by the error code displayed on the screen. This can also be caused by the tray not being fully closed on boot. E66: DVD Drive Error: DVD model, or version does not match that of the version expected by the dashboard. OR the firmware version on the drive is older then the firmware version expected by the dashboard. Make sure the DVD drive is of the same version originally included with the console and that it is using either the original firmware included with the console or newer. Try removing the hard drive and playing without it, This can also be caused by a Hard Drive Eprom Error. Some also believe this might be caused by a problem with the fans. If that does not work there is no other solution and the console must be sent back to MS for repair. There is a problem with the AV cable, try using a different AV cable. Turn the xbox 360 on, and wait till the 3 red lights are flashing.

Release the eject button and press it again. The LEDs will now blink the second number of the code. Release the eject button and press it again. The LEDs will now blink the third number of the code. Release the eject button and press it again. The LEDs will now blink the forth number of the code. Release the eject button and press it again. The LEDs will go back to the 3 red flashing lights. You should be able to determine the difference between the 3 flashing lights and the error code lights by the rate in which they flash. CPU, somehow the console isnt getting clean power from the power supply. Can be caused by problems with a firmware flash. This is also speculated to sometime be caused by a problem with the southbridge chipset on the motherboard. 0102 unknown error though its most likely GPU related literally means the console does not know what is wrong. DO NOT attempt either of these if your console is still under warranty. If your console is still under warranty return it to the store where it was purchased or call MS to have it replaced. Try removing the hard drive and playing without it 1010 Hard Drive Error, Can be caused buy a corrupt or missing eProm. There is a problem with the AV cable, try using a different AV cable. Internal and external desktop hard drives are the same.

Its just that external desktop hard drives comes in a shell that allows you to use it outside of the computer case. All desktop hard drives are mostly the same.

There is also a notebook hard drive which are smaller than desktop hard drives.