As per the article How the new Windows 8 license terms affect you:

You may transfer the software to another computer that belongs to you. … You may not transfer the software to share licenses between computers.

But what if I have a bunch of PCs with a mix of XP/Vista/Windows 7? Can I purchase either the Windows 8 Pro Upgrade $40 (download only) or $70 (DVD) version (both of which come without a key) only once and use it to upgrade all the PCs? Since I'm not sharing the license and each PC has its own valid genuine license, it should be allowed, right, or is it illegal? Even if they want people to shell out $40/$70 for each PC, how would they enforce the use of the installer/media on only one PC each?

I have been given to believe by a source that the installer will only check for the previous OS' key, which is what is confusing me (I have never purchased an upgrade version before this, only full retail or pre-installed versions). Is this true or will I need to enter two keys to make the upgrade work, one for the previous version and then one for Windows 8? If the latter is the case, then the issue is solved since obviously the same Windows 8 key will not be valid for multiple PCs.

  • 1
    answers.microsoft.com/en-us/windows/forum/… check that out I hope it will solve your issue. – avirk Oct 25 '12 at 9:38
  • @avirk: Yes, I believe it does. Thanks! It's clear now that the same installer/media can indeed be used (no obvious way to detect this as I surmised), but my source was wrong and every purchase of the upgrade will come with a Win8 license key. Also, it seems another source that stated that a clean install can be done with just the old OS key was wrong, since it seems the old OS needs to be installed for the license to be validated. So the old OS key will be auto-detected (don't need to enter it), the license validated, a format can be done and later the new Win8 key will need to be entered. – Karan Oct 25 '12 at 9:49
  • The important bit seems to be this: "You could purchase 3 licenses for $120. The Upgrade Assistant can create a bootable DVD if you want and you can use that same disc to upgrade multiple computers. When you make your purchase, you can specify the amount of licenses you want." Also this regarding clean installs: "First, you will need to reinstall the qualifying license, then start the upgrade again to Windows 8. Qualifying license means you will either need to reinstall Windows XP, Vista or Windows 7." – Karan Oct 25 '12 at 9:55
  • Yes that's the main part of that thread. I think its clear now for you. – avirk Oct 25 '12 at 9:57

You could buy a blank or thumbdrive and use that create a bootable media using the $40 upgrade. You could purchase 3 licenses for $120. The Upgrade Assistant can create a bootable DVD if you want and you can use that same disc to upgrade multiple computers. When you make your purchase, you can specify the amount of licenses you want.

Step 1: Use the Upgrade Assistant to qualify the PC and pay the $40 (US)

Step 2: When the "Install Windows 8" message appears, select "Install by creating media" to create a bootable USB flash drive or an .iso (a disk image) file. Step 3: Wait for the Assistant to download the Windows 8 Pro installation package and create the bootable media or .iso file. The flash drive must be have 3GB or more of free space available.

Step 4: Burn the .iso file, if that's the path you chose, to a blank DVD. Step 5: Use that USB drive or DVD to boot the PC.

Step 6: When you get to the screen in Setup that asks, "Which type of installation do you want?' choose "Custom."

Step 7: Select a disk partition for the OS in the next screen. At this point, you can create a new partition if there's enough space available, or reformat the drive.

Step 8: Continue with the installation of Windows 8 Pro.

You don't need a separate disk for each machine to install the Windows-8 you have just need the license key which MS provide you via mail after your purchasing.


  • Thanks, while all other answers helped me a lot as well and this is one of the times I wish I could upvote each answer more than once, the link provided here mirrored my scenario perfectly and answered all my queries. – Karan Oct 25 '12 at 18:11
  • Glad that it is helpful for you not a time waste :) – avirk Oct 25 '12 at 18:14
  • No-one should feel they wasted their time responding, even if their answer is not accepted. I have gathered lots of information from non accepted answers on this site, and sometimes they are often better than the accepted ones! Plus everyone who answers must also possibly have learnt something new during the process (hopefully). :) – Karan Oct 25 '12 at 18:21

You need to buy a new licence for each machine you are updating.

The download or DVD comes with one licence for one PC.

When you upgrade you will be prompted for the licence key that comes with the software. You may well be able to enter it multiple times (to allow for reinstallation) but when it is activated Microsoft will check and mark concurrent usages invalid.

  • But the upgrade version comes with no key at all, right? It depends on the previous OS version's genuine key to be validated. Since that key will be distinct for all PCs, what's stopping people from using the same installer repeatedly? Is there some way they are preventing/checking for this? – Karan Oct 25 '12 at 9:10
  • @Karan - Are you sure? The pre-release versions won't have the key, but I would have thought the full version would. – ChrisF Oct 25 '12 at 9:11
  • That's what I read somewhere, that only the System Builder versions will come with a key, whereas the upgrade versions will depend on you entering the old OS' key during install. Is that information incorrect? – Karan Oct 25 '12 at 9:13
  • @Karan I don't know. Hmm. It might be best to delete this answer then. I'd include the your additional information in the question to avoid others making the same mistake. – ChrisF Oct 25 '12 at 9:14
  • 1
    @Karan That is incorrect. Every consumer version of Win8 will require you to enter a valid Win8 key. If you are installing the upgrade version of Windows 8 on a machine that does not currently have a previous version of Windows installed, you will ALSO have to enter a valid previous version of Windows product key. If a machine already has Windows installed, it will auto-detect the previous key and you won't have to enter it. Either way, you will still have to have and enter a Win8 key. Also, it must be done during installation. There is no longer a 30 day grace period to activate. – BBlake Oct 25 '12 at 11:45

You can use the same installer to upgrade multiple PCs but you do need different keys and the upgrade license permits you to upgrade one installation of windows to windows 8. So no, you can't use it to upgrade multiple PCs.

From that article:

Anytime you transfer the software to a new computer, you must remove the software from the prior computer.

Whether you can technically or not, it is against the terms and I'd be surprised if it continued working for very long.

Regarding your edit, as Joel Coehoorn says in the comments, you do need seperate keys for each install.

If you have a lot of PCs to upgrade, maybe Volume Licensing could be an option.

  • Yes, but that's so that you do not share licenses (the part I quoted). In the scenario I mentioned, the licenses will be distinct, only the installer will be the same. Am I missing something obvious about how the installer will work? – Karan Oct 25 '12 at 9:11
  • The upgrade/installer used will be the same, that's the license you're buying and what can't be transferred. – George Duckett Oct 25 '12 at 9:14
  • Ok, so you're saying that I might be able to upgrade all the PCs, but won't be able to activate them all properly? – Karan Oct 25 '12 at 9:17
  • Yes. I believe that will be the case. Even if you can somehow activate them all I think you won't have legal copies anymore (apart from the orignal maybe). – George Duckett Oct 25 '12 at 9:18
  • You might be interested in volume licensing. – George Duckett Oct 25 '12 at 9:19

Not the answer you're looking for? Browse other questions tagged or ask your own question.