Replacing Twenty Ageing PCs: Which Licences Come With Them?

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A new business PC arrives with an OEM Windows licence and nothing else, and that licence never leaves the machine – the OEM terms permit transferring it to another user only with the licensed device. Microsoft 365 licences move by themselves because they follow the person. Everything in between has a rule worth checking before the order goes in.

1. Specify Windows 11 Pro on the quotation, along with TPM 2.0 and Secure Boot, and confirm them rather than assuming. Home cannot be Microsoft Entra joined and cannot have BitLocker enabled.
2. Do not plan to reuse the old machines’ OEM licences. They stay with the hardware being retired, including any authentic Windows label carrying the product key.
3. Check what a volume Windows build is sitting on. Upgrade licences require a qualifying operating system licence and the device must already have one installed – Windows 10/11 Enterprise, IoT Enterprise, Pro or Pro for Workstations.
4. Move Microsoft 365 users by signing in. Each licence covers five desktops, five tablets and five mobile devices, and past ten devices the least recently used is deactivated automatically – so sign out the retired installations.
5. Check the interval before moving a perpetual Office licence. A retail stand-alone copy may be transferred to another of your own devices no more often than once every 90 days, and must be removed from the previous one.
6. Recount CALs only if the refresh changes the number of people or devices reaching a server. A like-for-like replacement changes nothing.

Read each machine’s edition and channel with slmgr /dli, which displays licence information for the installed active Windows edition and needs no elevation. The evidence of an OEM entitlement is the hardware invoice, not a key read off the machine.

If the machines are quoted with Pro and your users are on Microsoft 365, the licensing side of this refresh is finished and the rest is a data migration. Below is what does and does not travel, the erase step, and what to do about machines that cannot run Windows 11.

Why it happens

A business-class PC ships with an OEM Windows licence whose key is written into firmware, so reinstalling Windows on that machine reactivates without anybody typing anything. That convenience is also the reason the licence cannot move: it belongs to the hardware. Microsoft’s OEM licence terms for pre-installed Windows 11 grant the right to install and run one instance of the software on the device for use by one person at a time, and permit transferring the licence to another user only with the licensed device – with the software and, where provided, an authentic Windows label including the product key.

What is in the box is decided at the point of order, not afterwards. A machine quoted with Home arrives with Home, and the correction is a separate Pro upgrade licence applied by hand. Across twenty machines that is a purchase plus most of a technician’s day, both of which disappear if the quotation says Pro. The reasons to insist are specific rather than vague: Windows Home editions do not support Microsoft Entra join – they can only be Entra registered – and BitLocker enablement is supported on Pro, Enterprise, Pro Education and Education rather than Home, though device encryption is available on all Windows versions where the hardware meets Modern Standby or HSTI requirements.

The rest of the estate divides cleanly into things that follow the person and things that follow the machine. Microsoft 365 follows the person: sign in on the new PC and the applications activate, within an allowance of five desktops, five tablets and five mobile devices per licence, with the least recently used device automatically deactivated beyond ten. CALs follow neither – they licence access to a server, so a like-for-like hardware swap does not change the count at all.

Full reference

Included, and not included

Which licences travel and which do not

• OEM Windows: does not travel. The terms permit transferring the licence to another user only with the licensed device, along with any authentic Windows label carrying the product key.
• Retail Windows: read the terms supplied with the copy you hold. Where a digital licence is linked to a Microsoft account, the documented reactivation route after a significant hardware change is the Activation troubleshooter, and the edition must match before and after.
• Volume Windows upgrade licences: travel within your agreement, but only onto devices that already hold a qualifying operating system licence underneath.
• Microsoft 365 apps: travel with the user automatically, within five desktops, five tablets and five mobile devices per licence. Sign out the retired installation so it does not sit in the allowance.
• Perpetual retail Office: may be transferred to another of your own devices no more often than once every 90 days, and must be removed from the prior device each time.
• Perpetual volume Office: reassignable subject to the Product Terms rule of not less than 90 days since the last reassignment of that licence, with exceptions for permanent hardware failure or loss and for a departing user.
• Antivirus seats: normally released when the product is uninstalled, though some vendors require the device to be removed in the console as well.
• CALs: unaffected entirely. They licence access to a server, not the endpoint doing the accessing.

Running the refresh without losing anything

1. Record what the old machines hold. slmgr /dli displays licence information for the installed active Windows edition, which tells you the edition and channel; slmgr /dlv gives the detailed version of the same thing. Neither needs elevation.
2. File the hardware invoices. For OEM entitlement the invoice is the evidence, not a key read off the machine.
3. Order the new machines with Windows 11 Pro, TPM 2.0 and Secure Boot, and confirm those on the quotation rather than assuming them.
4. Build one machine first. Confirm it activates from firmware with nothing typed in, then enrol or image the rest from that known-good starting point.
5. Move the users: sign in with the Microsoft 365 account, let known folder redirection carry desktop and documents into cloud storage, then check printers, add-ins and any local data files.
6. Retire the old machines: remove the device records from your directory and management tooling, release the antivirus seats, then erase the disks.

Microsoft’s published class reference for the SoftwareLicensingService WMI class does not list a property for reading the firmware product key, and WMIC – the tool usually used for it – is being removed from Windows in favour of PowerShell. Do not build a process on either. Use slmgr /dli for what the machine believes it is, and the hardware invoice for what you are entitled to.

Erase the retired machines before they leave the building. Removing a device object from your directory does not touch the disk, and an encrypted drive whose recovery key is still held in your tenant is not the same thing as a wiped one. If the machines are being sold or donated, a documented erase is part of the job rather than an optional extra.

Which route to take, by situation

• Twenty machines, already on Microsoft 365 with a management plan: order Pro, enrol on first boot, and buy nothing per machine except the operating system.
• A perpetual Office estate: check the 90-day reassignment interval before planning a rolling refresh around it, or treat the refresh as the natural moment to move those users to a subscription instead.
• Machines that arrived with Home: Pro upgrade licences, applied at Settings, then System, then Activation.
• Old hardware that cannot run Windows 11: replace it. Commercial ESU runs a maximum of three years past 14 October 2025, and consumer coverage ends on 12 October 2027.
• Refurbished purchases: insist on documented licences, and confirm the machine activates from firmware before it is deployed rather than afterwards.
• A refresh that also changes headcount: recount CALs, because that is the only thing here that moves them.

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