I have upgraded to Windows 10 Pro x64 - Now I need to replace motherboard and RAM

Question

I have upgraded my from Windows 7 to Windows 10, then I carried out a clean install. All worked fine.

I am now going to plan an upgrade of my Motherboard, Processor, RAM and Video Card.

Obviously I will need to clean install my Windows 10 again. Therefore, given teh fact that those who upgraded didn't get a new licence key, how should I handle the Windows Activation process?

Can I use my old Windows 7 licence key?

Answer 1

While I'm sure no one knows the answer to your question at this time, I can summarize all the information there is on the Internet regarding this, as I have done a good amount of research into this topic.

Assuming you have a Retail License, there are a few answers from the Internet. Before that, though, I would like to quote the Section 4 Part B of the Terms for Windows 10.

If you acquired the software as stand-alone software (and also if you upgraded from software you acquired as stand-alone software), you may transfer the software to another device that belongs to you. You may also transfer the software to a device owned by someone else if (i) you are the first licensed user of the software and (ii) the new user agrees to the terms of this agreement. You may use the backup copy we allow you to make or the media that the software came on to transfer the software. Every time you transfer the software to a new device, you must remove the software from the prior device. You may not transfer the software to share licenses between devices.

The issue is that the terms do not specify how to go about transferring the license to new hardware. It also doesn't specify whether or not there is a time-limit (more on this later). Now that we have what the official terms say, below I summarize what others (including Microsoft Officials, whose words are obviously not legally binding).

For completion, I will include here the answer by Microsoft Rep basically re-quoting the Terms in a different way. He states that if you upgraded from a retail license, you retain the transfer rights. But he does not specify how to go about doing so (and that is the question we all want to know...).

Because I don't have enough reputation, I cannot post more than 2 links. So, the links to the sources of the Scenarios are posted in the comments, in order.

Scenario 1 : There is a Time Limit

Basically, you are free to install your retail key of Windows 7 to any machine and upgrade it to Windows 10 before 2016.07.29. After that, the machine you have the upgraded version of Windows 10 will still be usable, but you can no longer upgrade to Windows 10 from your Windows 7 key. That is, if you install Windows 7 using your key to any machine (including the machine already running the upgraded Windows 10), you will not be able to upgrade.

Scenario 2 : There is no Time Limit, but Machine Limit

In this case, there is no time limit. You can upgrade to Windows 10 from your Windows 7 key, provided that you do it on the latest machine that Windows 10 is installed on before 2016.07.29. In other words, after 2016.07.29, the machine that the upgraded Windows 10 is installed on will be able to upgrade to Windows 10 should you install Windows 7 on it again. However, this will NOT apply to any other machine you install that same key of Windows 7.

Scenario 3 : There is no Time Limit, and no Machine Limit

In this case, there is no time limit, and also no machine limit. Basically, once you "take" the Windows 10 upgrade from a Retail License, you have it forever. The Microsoft Server will associate your key with the fact that you have accepted the Windows 10 Free Upgrade offer. In other words, you are now able to install your Windows 7 key on any machine (even after 2016.07.29), and then be able to upgrade to Windows 10. Note here, you have to go from Windows 7 to 10, you cannot just install Windows 10 and use your Windows 7 key. Also note, the source of this scenario is the same as that of Scenario 2, and the poster of this information is also the same guy! So I'm not sure what he's cooking. But he is a Microsoft Rep.

Scenario 4 : The Previous Key Works

At this time, I cannot find the source of this. But I'm sure you've already seen this. Apparently, you can use your Windows 7 key to install Windows 10. But some people claims this does not work. One possibility (if this scenario is correct) is that you have to upgrade to Windows 10 through Windows 7 at least once, and THEN you can use the key. I have not tested this, and I have not seen other people test this (correct me in the comments and I will update). It is very unlikely this is the correct scenario though.

In conclusion, I think either Scenario 1 or Scenario 2 is the most likely case.

Answer 2

Can I use my old Windows 7 license key?

No; There is a solution.

Your only real option would be to install Windows 7 Service Pack 1 and then upgrade that installation to Windows 10. Once activated you could in theory migrated your current installation to the new machine if you wanted with the appropriate software.

1. Your Windows 7 license key cannot be used to install Windows 10 for obvious reasons.
2. Your Windows 7 license cannot be used to activated Windows 10 for obvious reasons.
3. Your Windows 7 license can only be migrated to this new motherboard if its a retail license.

If your Windows 7 license was an OEM license then you will need to go out and purchase a retail installation of Windows 10. You could at that point migrated your current installation and just change the license to the key you purchase. This is a more technical and time consuming process then the solution I recommend.