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.

Each Network Interface Card has unique MAC Address. All the components in the computer have a ROM which stores the serial number of the product. The OS stores all these details during installation and during activation. The serial key is responsible for protectiting software piracy along with the activation which determin the HOME of the OS.

The activation has some threshold limitations. ROM It then calculates and records a number based on the first device of each type that was found during setup, and stores this number on your hard drive. Product Key used in setting up Windows. The hardware is checked each time Windows boots, to ensure that it is still on the same machine. If your hardware is substantially the same, this will be done by an automated call without your needing to talk to anyone. So, for example, you can install a new video display card every month for as long as you like.

NIC and then reboot, you may be missing its three votes and find that a new activation is needed. NIC is back in service. If, on Windows startup, there are not the required seven Yes votes, the system will, in the original version of Windows XP, only boot to Safe Mode. You will be required to reactivate by a phone call to Microsoft.

This will reactivate your copy of Windows. Pack 1 has been installed: The system will continue to boot normally for three days, during which time you will be able to contact the activation center via the net. It is worth getting the freeware utility Volume ID to restore the original VSN. Then, after the reformat and new Windows XP installation, defer the new activation until you have run Volume ID to restore the old VSN, and rebooted. 2: Another thing that changes the VSN is converting a FAT 32 partition to NTFS. So, if you upgrade a system using FAT 32 to Windows XP and intend to convert to NTFS, do the conversion before activating the system. Remember, you can wait a while: you have 30 days before you need to activate. Or, if you have already activated, use Volume ID as described in Hint No. BAK files, as described in Hint No. Win XP, these files can be copied back to restore the prior activation status. However, this only works in those limited circumstances. The disk drive and partition recorded will be the ones that the system has found first when doing the initial activation: normally the one from which the system booted. So, if you change that disk and reinstall Windows to a new partition, you have lost two of the Yes votes. This is because it searches for all disks, and the vote will be Yes in both categories if it finds the original one, with the partition not reformatted. You can format any number of times; it does not damage your disk any more than normal usage. Formatting a hard disk simply creates a file system on the hard disk and maps logical disk sectors with physical disk sectors. Because of the way they address sectors, they cannot manage modern large hard disk volumes. NTFS is a newer file system that is much more robust and can manage larger volumes. There are many other file systems; these are just the two most common examples.