If you have already built a computer and bought a Windows license, you probably will not want to buy another license for the next one. With the slmgr command, you can disable your old PC and activate a new one.
Disable an old PC instead of buying a new license
Windows licenses are expensive. Between $ 100 and $ 200, an official Microsoft product key costs about the same price as a hard drive in the solid state of 1 TB, 16 GB of RAM or a motherboard. And it's not a good idea to buy cheap keys on inaccurate sites. So paying for another license when you want to decommission an old computer for a new one is not a good option. The good news is that it is possible to disable a PC that you no longer intend to use, and then transfer that license to a new computer.
the slmgr command makes it pretty simple, but you have to keep in mind some limitations. This will not work for OEM keys, which come with a computer that you bought at a store. Manufacturers integrate these keys with the hardware on which they were created, and transfer them to new devices will not work. And although slmgr can disable any retail key (a key that you have purchased separately), it will only activate a key that matches the installed operating system.
Windows 7 and 8 keys will always be activate Windows 10, but only via the standard activation process and not via slmgr. If you enter a "Pro" key on a "Home" installation, this will also fail with slmgr. To make tasks as easy as possible, transfer a Windows 10 Home key to a Windows 10 Home device and a Windows 10 Pro key to a Windows 10 Pro device. Otherwise, you will have to take additional measures.
How to disable your old PC
Before you begin, make sure your Windows key is registered somewhere. If you have a product box or digital receipt, pick it up from there. If not, there are a few ways you can recover the product key from your old PC, including using Produkey from Nirsoft.
To disable your old PC, you must open a command prompt with elevated privileges. Having an administrator account is not enough. You will need to click the Start button and type "cmd" (without quotation marks) in the search field. Then click on the "Run As Administrator" option on the right.
In the command prompt that appears, run the following command, and then restart your computer:
slmgr.vbs / upk
If you plan to sell the machine or give it away, you may also want to erase the registry key. It is not strictly necessary to disable, but it is a good idea to protect your key.
Type the following in the command prompt:
slmgr.vbs / cpky
If the commands are successful, your old PC will be disabled. You can still use Windows, but this will not be treated as a authentic copy Windows and some features will not work, such as desktop customization. You will be in the same state as the installation Windows without product key. If you want to activate Windows, you can buy a new key and enter it, or buy one from the Windows Store.
How to activate a new PC
To enable it with the help of slmgr, open a command prompt with elevated privileges and run the following command:
slmgr.vbs / ipk ##### – ##### – ##### – ##### – #####
Just replace ##### – ##### – ##### – ##### – ##### with your key.
If you try to use a key that has not yet been disabled on a previous PC, it may seem to work initially. But the activation will eventually fail and you will receive "non-genuine" and "renewed your PC" notifications.
Again, this will only work if the key exactly matches the operating system you are using. If you have a Windows 10 Pro key but Windows 10 Home is installed, you will simply encounter an error regarding non-core Windows.
And if you try to use a previous version key, such as Windows 7 or 10, you will receive an invalid key error.
The best thing to do in these cases is to open the settings, click on the "Activate Windows" option, then enter your key manually.
Note that if you use a Pro key and activate an installed copy of Windows 10 Home, this method will automatically switch to Pro.
Do not forget that you can only use Windows keys for one installation at a time and plan in advance. If you want to keep your old computer during construction, you will need a second Windows license. But if the plan is to downgrade, save money and transfer your existing license.