How to do a clean installation of Windows 10 instead of an upgrade and still be licenced
Since Windows 10 was launched, Microsoft have offered a free upgrade for computers running Windows 7, 8 or 8.1. This offer expires on 29th July 2016 and after that, the cost for Windows 10 Home will £99.99.
The upgrade process assumes you will run do an in-place upgrade (if you are fed up of being nagged about it, remove KB3035583!). As part of this, it ensures that your existing copy is licenced and that the new version will also be licenced. As part of this upgrade, your computer is registered with Microsoft (so you require Internet access), so if you subsequently do a clean install it will be automatically activated.
You may not want to do an in-place upgrade for a number of reasons:
- You don't have the disc space for the upgrade files, the new version of Windows and the old version of Windows to be present at the same time.
- You want to upgrade at a convenient time when you believe that Windows 10 is good enough for your needs
- You may want to install on a different disc
- Windows may refuse to upgrade on your hardware even though a clean install works (e.g. it claims a graphics card is not supported)
If you do a clean install, then you will be asked to enter a product key. If you previously did an in-place upgrade, you can click Skip and the computer will be automatically activated. If installing from a recent build of Windows 10 (build 10565 or later), you will be able to use your existing Windows 7, 8 or 8.1 product key to activate. However, it is not clear how this works with the upgrade offer; will existing codes be rejected after 29th July?
One way to play it safe is to manually run the registration process on your existing activated installation of Windows. This will generate a file called
GenuineTicket.xml which you can store somewhere safe and copy back on to activate your new installation. This will work with all versions of Windows 10, not just recent builds.
- Check you have a working Internet connection
- Locate a Windows 10 ISO or DVD
- Open the ISO image or DVD and go into the
- Copy the file called
gatherosstate.exeto your hard disc (e.g. onto your desktop).
- Right-click on the copy of
gatherosstate.exeand choose Run as administrator. N.B. do not try to run the copy from the ISO or DVD
- If you see a User Account Control window, click Yes to confirm you want to proceed
- After a while, a file called
GenuineTicket.xmlwill be created alongside the
GenuineTicket.xmlto a safe place off your computer (e.g. a USB stick) as when you re-install the disc will be wiped
- Do a clean install of Windows 10
- When prompted for a product code, click Skip
- After installation, open File Explorer and go to:
- Copy your
GenuineTicketfolder. You will probably be asked to confirm that you wish to copy
- Restart the computer
- Check the activation status by going to the System control panel and looking at the bottom of the window (you may also run
slmgr /xprfrom a command prompt to check it).