How to transfer a retail Windows licence to a new PC

Only a Retail licence is designed to move between PCs — check our companion guide first if you're not sure which type you have. If it's Retail, here's the process.

Before you start

Sign in to Windows with a Microsoft account on the old PC before you transfer, if you haven't already. Linking the licence to your account makes reactivation on the new PC far more reliable, since Windows can then recognise the licence as belonging to you rather than only to that specific device's hardware fingerprint. If your current install is signed in locally rather than with a Microsoft account, add the account link now under Settings → Accounts → Your info, before moving on.

Step 1: Deactivate on the old PC

On the old PC, open an elevated Command Prompt and run:

slmgr /upk

It's worth being precise about what this command actually does: it uninstalls the product key from the local Windows installation on that machine. It does not itself contact Microsoft's activation servers to release or re-flag the licence for use elsewhere, and running it is not by itself a guarantee that the licence will be recognised as available when you activate on the new PC. What actually determines whether reactivation on new hardware succeeds is the licence being linked to your Microsoft account (see "Before you start" above) and, for some scenarios, using the Activation Troubleshooter on the new PC afterward. Running slmgr /upk is still good practice — it cleanly removes the key from the old machine and avoids confusion about which installation is currently using it — but treat it as tidying up the old PC, not as the mechanism that authorises the new one.

Step 2: Install Windows on the new PC

Install the same edition (Home or Pro must match what your licence covers — see our Home vs Pro guide if you're unsure) on the new hardware. You can do this before or after step 1.

Step 3: Activate

Go to Settings → System → Activation. If your licence was linked to your Microsoft account, sign in with that same account during or after setup, and Windows will often activate automatically once it recognises the linked entitlement. If not, select Change product key and enter your key directly.

If it doesn't activate automatically

Go to Settings → System → Activation → Troubleshoot, and select "I changed hardware on this device recently." This flow is specifically built to reconcile a licence that Windows doesn't yet recognise as valid for the current hardware, by checking it against your signed-in Microsoft account. If you're signed in with the account the licence was linked to, this resolves the great majority of hardware-change cases without needing to contact support.

If it still won't activate

Double-check you're using the exact product key associated with your order, and that the Windows edition installed on the new PC matches the licence exactly (Home vs Pro mismatches are a common, easily-missed cause). If the troubleshooter still can't validate it, our companion guide to common activation errors covers the specific error codes people run into at this stage, and what each one actually indicates.