This means two generations back from the licence provided, so with Windows 10 Pro licenced units the user can actually install Windows 7 Pro. There is however one drawback to all of this: the user who wants to exercise their downgrade rights and install an earlier version of Windows.įrom Windows 10 Pro the user (that’s you constant reader) has the right granted from Microsoft to install an OS that is N-2 in revision. The DPK also has benefits as it makes auditing licences easier via the KMS (Key Management Server), especially in Volume Licenced organisations – if there is no DPK with corresponding SLIC tables for Windows 8/8.1/10 Pro then no activation of the volume media. So, we now have a secure OEM licencing system and the user cannot see or lose their licence key when a new system board is fitted the DPK is supplied already in the new board. The CoA sticker became a thing of the past, relegated to the dustbin and was replaced by a Windows Logo on the base on the notebook instead. As a result the OEM Operating System was intrinsically linked to the product it came with and no more could any CoA to hand be used when installing Windows 7, or could we deploy a modified version of OEM Window 7 via Sysprep. Use of a DPK was introduced by Microsoft with the launch of Windows 8 and saw the 25-character key injected into the PC system board. The introduction a number of years ago of the Digital Product Key (DPK) saw the removal of the Certificate of Authority (CoA) Licence Key sticker we had all grown to know and love since the days of Windows 95.

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