Explained: New Motherboard, CPU. Do I need a new license / reinstall Windows?

Infopackets Reader Steve F. writes:

" Dear Dennis,

I will be upgrading my computer to the new AMD Ryzen 1700 CPU (which has 8 cores and 16 threads!) at a fraction of the price of Intel CPUs. I have searched online but I can't seem to find the answer - can you please tell me: after I install the new motherboard and CPU, can I continue to use my existing Windows installation or do I need to install Windows again? Also is my Windows 10 license still valid or do I need to purchase Windows 10 for my new motherboard and CPU? "

My response:

Short answer: It depends on the type of Windows you own and/or whether you are replacing the motherboard with the exact same model / revision.

Long answer:

In general, Microsoft considers a new motherboard upgrade to be a new machine, though if you go with the EXACT same motherboard (with same revision) it may not be flagged as a "new motherboard". Also, whether or not you have to purchase a new license depends on the type of Windows installation you have.

OEM Windows + New Motherboard = New Windows License Required (99% of the time)

For example: If you installed Windows 10 OEM from a "system builder dvd" onto an older system and then decided to replace it with a brand new motherboard and CPU, then you have to buy Windows 10 for that new motherboard and CPU.

If your computer is a Dell, HP, Compaq, etc, then this is an OEM Windows version. OEM stands for "Original Equipment Manufacturer". You can buy "OEM" versions of Windows 10 from Amazon (for example) as a "System Builder DVD" for use with new computer builds.

If you installed Windows 7 OEM and upgraded to Windows 10, it is still considered OEM.

In some cases, if you replace the motherboard with the exact same model and hardware revision as the previous motherboard (if your computer was struck by lightning, for example), you may not need a license, but this is a craps shoot.

Full Retail Windows + New Motherboard = No New License Required

Let's look at yet another example.

If you purchased a full retail version of Windows 7 or 8 on DVD and you upgraded to Windows 10, then your Windows 10 is still considered a full retail version. Therefore, you can transfer the license to a new machine / motherboard. However, you will still need to reinstall Windows clean because the old Windows installation likely won't work on the new hardware (I'll explain more about that below).

In this case, you will most likely have to activate Windows over the phone by calling Microsoft and tell them you've upgraded your motherboard. When this happens, your activation code on your old system is revoked and becomes invalid; Microsoft will then provide you with a new activation code for the new system.

"Can I Boot my Old Windows on my New Motherboard and CPU? "

Short answer: MAYBE, but it's probably not going to work properly and/or crash on you repeatedly. Also, your license may be invalid for reasons I've clearly outlined above.

Long answer:

You might be able to get away with booting from your old Windows installation, but chances are it will: fail, not boot at all, won't be stable, or it will produce strange error messages. That's because each installation of Windows is unique to the computer it's being installed on and contains specific drivers and hardware settings for that computer. If you change the motherboard, then all of those settings are no longer valid.

There are programs such as Acronis True Image which has "Acronis Universal Restore", which allows you to transfer your operating system onto a new machine with dissimilar hardware, but the process is somewhat complicated and not guaranteed to work.

Migrating Windows from and Old System to New

The best approach when migrating to a new machine is to make a disk image or virtual machine of your existing system before the upgrade, and then copy over your user data from the backup / virtual machine onto the new system.

You will then need to reinstall all your programs on the new system. This is the only 100% sure-fire way of upgrading without running into any of the problems I just mentioned. If you need help with this, I can assist using remote desktop support - described next.

Additional 1-on-1 Support: From Dennis

Based on my experience, migrating Windows from an old machine to a new machine takes many hours to complete, and can sometimes take a few days. If you need help migrating your existing system to another, or need help reinstalling Windows, I would be more than happy to assist you using my remote desktop support service. Simply send me an email briefly describing your message and I'll get back to you as soon as possible.

Got a Computer Question or Problem? Ask Dennis!

I need more computer questions. If you have a computer question -- or even a computer problem that needs fixing - please email me with your question so that I can write more articles like this one. I can't promise I'll respond to all the messages I receive (depending on the volume), but I'll do my best.

About the author: Dennis Faas is the owner and operator of Infopackets.com. With over 30 years of computing experience, Dennis' areas of expertise are a broad range and include PC hardware, Microsoft Windows, Linux, network administration, and virtualization. Dennis holds a Bachelors degree in Computer Science (1999) and has authored 6 books on the topics of MS Windows and PC Security. If you like the advice you received on this page, please up-vote / Like this page and share it with friends. For technical support inquiries, Dennis can be reached via Live chat online this site using the Zopim Chat service (currently located at the bottom left of the screen); optionally, you can contact Dennis through the website contact form.