I have worked out that a company I am working for is using the same product key on all its computers. They are all Windows 7 Enterprise PCs. Is this legal for them to be doing this?

2 Answers 2


Volume Licensing

Windows 7 Enterprise is only available through the Volume Licensing (VL) channel. Unlike other editions which are available through OEM or retail channels, a single key can be used for multiple activations.

With Volume Licensing for products such as Windows 8.1, Windows Server 2012 R2, Windows Server 2012 R2 for Embedded Systems, Windows 7, Windows Server 2008 R2, Windows Vista, Windows Server 2008, Microsoft Office 2010, and Office 2013, you must use Volume Activation (VA). To activate these products with VA, you can use either a Multiple Activation Key (MAK) or Key Management Service (KMS).

Source: Microsoft Volume Licensing - Product Activation


A MAK is used for one-time activation with Microsoft's hosted activation services. Each MAK has a predetermined number of allowed activations; this number is based on Volume Licensing agreements and does not match the organization's exact license count.

Source: Understanding MAK Activation


Through KMS, organizations set up a local KMS host (or hosts) that connect once to Microsoft to activate the KMS host(s). Then the individual systems throughout the organization connect to the KMS host(s) and activate transparently.

With KMS, client computers connect to the local KMS host to activate the first time, then they reconnect periodically to keep the activation current. KMS is capable of activating an unlimited number of computers, so it can be used for a VL agreement of any size.

Source: Windows Activation Technologies in Windows 7

Further reading

  • Thanks with a volume licence would all the pc's use the same key or would a different one be issued for each.
    – Nato51
    May 19, 2014 at 12:18
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    @Nato51 They would use the same. If the activation is MAK-based, all clients would share a single activation key (assuming they're within the activation limit); if the activation is KMS-based, all clients would share a predefined setup key, while the KMS host would handle the actual activation through a KMS key.
    – and31415
    May 19, 2014 at 13:28
  • The problem is with predetermined number of allowed activations; this number is based on Volume Licensing agreements. I have MSDN BizSpark subscription and I can't find the limit of my Windows 10 MAK key anywhere. I've read that for MAK keys even reinstalling on the same PC with the same hardware affects the remaining activations count, while Retail keys can be activated without limits on the same hardware, but I'm not sure if this is true. I guess, time will tell - if MAK key stops working, I can use the Retail one. Or vice versa. Jul 29, 2015 at 15:26

Generally speaking you can use the same key and it will work, but of course Microsoft won't like you for it. Strictly speaking if they ever decided to audit your product key it could be revoked, but of course I have never heard of any case in which this has occurred. You can get a rough idea from Microsoft forums on where they stand on the issue.

As pointed out in comments I preface this looking at your specific reference to Windows 7 Enterprise which is available only through Volume License Center and can use a single activation key to install multiple systems.

  • Is it illegal or does Microsoft just not like it.
    – Nato51
    May 19, 2014 at 9:55
  • As you can imagine Microsoft want you to buy lots of licenses. If they find you using the same key twice they can revoke it, but you aren't pirating software or stealing a key, so it isn't illegal. May 19, 2014 at 9:57
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    Windows 7 Enteprise is only available to Volume License costumers. Volume License Keys (VLK) are meant to activate multiple systems, so no reason "Microsoft won't like you for it."
    – and31415
    May 19, 2014 at 11:03
  • @and31415 | I stand corrected. Just checked my VLKs and you are indeed correct. Thanks. May 19, 2014 at 11:06
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    @and31415 they still won't like it if you use the key on more systems than you paid for May 19, 2014 at 12:29

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