In general, OEM software may not be transferred from one system to another system. However, the computer system can certainly be updated with new components without the requirement of a new software license. The only exception to this is the motherboard .. If the motherboard is replaced the computer system is deemed "new" and a new license would be required.
Other PC components may be upgraded, including a hard drive. Though if the hard drive is replaced/upgraded, the operating system must first be removed from the old hard drive. To restate: the operating system is "married" to the computer system on which it is originally installed.
Windows Product Activation is what Microsoft calls the technology it created to cut down on so-called casual copying of its software--for example, installing the same license on several PCs in a home or small office. WPA creates a numeric identifier of a PC's hardware by looking at ten different components.those components on your "new" system would ALL be different...I don't remember them all by heart but the CPU ...NIC...CHIPSET...HARD DRIVE are part of them
That data is transmitted to Microsoft along with the product key, the 25-character code found on the installation CD that users enter during installation. (Those who don't have Internet access must call Microsoft and read both long numbers to a representative). Subsequently, if the OS is reinstalled--say, after an upgrade--WPA generates the numeric identifier again and sends it to a Microsoft server that checks it against the original identifier. If the two are significantly different, the PC can't be used until another call is made to Microsoft.
People who buy new PCs with Windows XP preinstalled are even less likely to run into Windows Product Activation challenges. When XP is factory-installed on a PC, it identifies the machine solely by looking at its BIOS. Users would have to swap out the motherboard for one from a completely different vendor before the PC would identify the action as a reinstall and require contact with Microsoft to continue.
Edited by happyrck, 15 December 2007 - 10:03 AM.