The limitation on number of machines is the same, regardless of the version: Only one machine at a time. You CAN delete the OS from one machine and install it on your replacement machine as many times as you wish.
I'm not convinced this is correct.
Investigating the meaning of OEM licenses from MS reveals the following:
(1) These are called OEM Licenses and of course they come with more restrictions since they are the cheapest. An OEM license only allows you to use the software on the specific computer it came with. In other words, when that computer is old and slow and it is time to throw it away, that license must legally be thrown away as well.
(2) Q. What computer component ties the OEM license to the computer?
A. Short answer – the first motherboard the OS was installed on. In the case of your purchase of an OEM license with a new computer, this license is tied to the motherboard of that system. In the case of a purchase of OEM software from a retail seller, this would be the first motherboard you install the software on, *not* the “hardware” that was bundled with your OEM purchase.
Q. Can a PC with OEM Windows XP have its motherboard upgraded and keep the same license? What if it was replaced because it was defective?
A. Generally, you may upgrade or replace all of the hardware components on your customer's computer and the end user may maintain the license for the original Microsoft® OEM operating system software, with the exception of an upgrade or replacement of the motherboard. An upgrade of the motherboard is considered to result in a "new personal computer" to which Microsoft® OEM operating system software cannot be transferred from another computer. If the motherboard is upgraded or replaced for reasons other than a defect, then a new computer has been created and the license of new operating system software is required. If the motherboard is replaced because it is defective, you do NOT need to acquire a new operating system license for the PC.
Q. Can my customers transfer or sell their OEM software licenses?
A. After an OEM software license has been installed on a PC, the license may not be installed on or transferred to another PC. However, the entire PC may be transferred to another end user along with the software license rights. When transferring the PC to the new end user the software media, manuals (if applicable) and certificate of authenticity label must be included. It is also advisable to include the original purchase invoice or receipt. The original end user cannot keep any copies of the software.
The end user license agreement (EULA) is granted to the end user by the System Builder and relates to the license on the PC with which it was originally distributed. Because the System Builder is required to support the license on that original PC, a System Builder can not support a license that has been moved from a PC they manufactured to one that they did not. This is one of the key reasons why an OEM System Builder license can’t be transferred.
Q. My customer bought a new PC and wants to move their OEM software from the old PC to the new one. Can't they do whatever they want with the software?
A. The software is licensed with the computer system on which it was originally installed and is tied to that original machine. OEM licenses are single-use licenses that cannot be installed on more than one computer system even if the original machine is no longer in use. The end user license agreement (EULA) accepted by the customer before they use the software, states that the license may not be shared, transferred to or used concurrently on different computers. The System Builder is required to provide end-user support for the Windows license. A System Builder can not support a license that has been moved from a PC they manufactured to one that they did not — this is a fundamental reason why OEM System Builder licenses can't be transferred."
(3) PRODUCT SUPPORT. Support for the SOFTWARE is not provided by MS, Microsoft Corporation, or their affiliates or subsidiaries. For SOFTWARE support, please refer to Manufacturer's support number provided in the documentation for the HARDWARE. Should you have any questions concerning this EULA, or if you desire to contact Manufacturer for any other reason, please refer to the address provided in the documentation for the HARDWARE.
Basically OEM copies receive no support directly from Microsoft. Rather you must refer to your place of purchase for support *if* they provide such support. Please note that support *generally* comes from smaller OEMS who provide the software bundled with a computer.
(4) "1-2 CPU" labeling.
Some copies of Windows XP have labeling such as "1-2 CPU", this labeling has caused some confusion and misconceptions about what "1-2 CPU" stands for. I direct you to the following excerpt directly copied from the EULA.TXT on any *generic* Windows XP machine:
"Installation and use. You may install, use, access, display and run one copy of the SOFTWARE on the COMPUTER. The SOFTWARE may not be used by more than two (2) processors at any one time on the COMPUTER, unless a higher number is indicated on the COA.
The above statement is clear in that the labeling of "1-2 CPU" means the number of processors on a *single* computer and not that you can install the same copy on two different computers.
I think it's clear... use once and discard.
