Requirements for re-upgrading to Windows 10

[superFoolish]

Short version...

I have an old (2010) PC currently running Windows 10 Professional (free upgrade from Windows 7 last year), and I now want to downgrade to Windows 7. I have everything required for a 'clean' Windows 7 installation (i.e. reformat and start from scratch), but I would like to retain the ability to upgrade to Windows 10 again at some point in the future.

I have run Belarc Advisor to get the Windows 10 key. Do I need anything else in order to 're-upgrade' to Windows 10 if required?

Secondary question relating to Windows 10 licensing... Now that the free Windows 7 to Windows 10 upgrade has ended, what's the chances that I could use this Windows 10 key to upgrade a different PC that is currently running Windows 7?

Longer version...

The PC in question sits behind our TV and is used for media streaming. Its performance has been adequate, but the latest Windows 10 update keeps failing, and I'm sure performance is now more sluggish. For my purposes Windows 7 is fine, and will run without nagging for updates. If the PC lasts until Jan 2010, when Windows 7 no longer receives extended support, I'll reconsider my options (only 18 months away!).

Up until recently, we had been accessing the PC directly to play movies, etc, (i.e. PC is plugged into one of the TV's HDMI ports, and we controlled it with a remote mouse). However, with the advent of ChromeCast, I plan to move the old PC into the 'communications cabinet' (aka spare-room top-shelf) and connect it directly to the modem-router. It will then be used solely for ChromeCasting via Plex.

I could probably just install Plex on Linux, but I am not a Linux afficionado (I know the basics from using a Raspberry Pi), and I don't have the time to mess around with it at the moment. I know that I can install Windows 7 and have a Plex server running on it within an hour or so. Plex on Linux can wait until I have more time on my hands.

Incidentally, this is my longest-serving (and longest-running) PC, an Acer Revo; a neat little box that has been sitting behind our TV for nearly 10 years, in its original form, with no upgrades, and no failures. I bought it from Ebuyer six months before we moved from the UK to Australia, so it's also well-travelled!

[Breelander]

I have an old (2010) PC currently running Windows 10 Professional (free upgrade from Windows 7 last year), and I now want to downgrade to Windows 7. I have everything required for a 'clean' Windows 7 installation (i.e. reformat and start from scratch), but I would like to retain the ability to upgrade to Windows 10 again at some point in the future...

You have it already, there's nothing you need to do in preparation.

When you took the free upgrade a digital licence was stored on Microsoft's activation servers. This licence is linked to the unique hardware ID of the PC. The licence is valid for the 32 and 64 bit versions of the edition you originally got (Home or Pro). The HDD is not part of the hardware ID, so you can replace it with a new HDD or SSD and still be licenced.

To clean install Windows 10 at any time in the future, just install the same edition as you had before, in your case Windows 10 Pro. When asked for a key, click the 'I don't have one' link to complete the install. As soon as Windows can connect to the activation servers it will activate automatically from your digital licence.

I have run Belarc Advisor to get the Windows 10 key. Do I need anything else in order to 're-upgrade' to Windows 10 if required?

Secondary question relating to Windows 10 licensing... Now that the free Windows 7 to Windows 10 upgrade has ended, what's the chances that I could use this Windows 10 key to upgrade a different PC that is currently running Windows 7?

None whatsoever, not if the key is the one ending with 3V66T. That is the generic Windows 10 Pro key and won't activate anything (the one for Home ends with 8HVX7). All PCs that took the free upgrade got a generic key. The digital licence is your true 'key' now.

But you don't need a key, you can still upgrade a qualifying Windows 7/8 PC. I have seen it reported as recently as last month that if you use the Windows 10 install media to upgrade a Win7/8 PC it will still get activated with a digital licence, despite Microsoft saying that the free upgrade was only on offer for a year.

Go to https://www.microsoft.com/software-download/windows10 and download the Media Creation Tool. Run it and choose the option to 'make media for another PC'. By default it will make media in the bits/language of the PC running the MCT. If the target Win7 PC is a different bits (eg 32 instead of 64) or a different language then untick the box for 'make media to suit this PC'. Make the media as a USB, plug it into the PC to be upgraded while Windows 7 is running. Find Setup.exe on the USB and run it to start the upgrade. Remove the USB when setup says it's about to reboot - you don't want to boot from the USB at that point, you should boot from the HDD to continue the upgrade.

[superFoolish]

Thanks for the detailed response, Breelander. Much appreciated.

[superFoolish]

Just another word of thanks to Breelander, following the advice on Windows 10 upgrades and licensing; Windows 10 upgrades from Windows 7 are still activating for free, based on my experience today...

I finally got round to upgrading my main PC from Windows 7 to Windows 10. I've had the PC for about 5 years now, but it was a high spec machine at the time, and it's running nicely (i5-3330, 3GHz, 32Gb RAM, recently upgraded to SSD as boot drive and a more powerful graphics card), although it sounds as though the fan is running at high speed 100% of the time. Not sure what I can do about that; it could be a problem, as I use the PC for Audio recording (voice).

The Windows 7 (Ultimate) installation was actually a TechNet license that I purchased legitimately almost 10 years ago for GBP170, when I was doing IT tech stuff. Technically, I should not have been using it for 'production' purposes, but upgrading it has provided me with a valid Windows 10 Professional license. Back in those days, TechNet product licenses didn't have an expiry date, so they are valid forever (not so for later TechNet subscriptions), so I have had very good value out of it.

Ironically, I also downgraded my 9 year-old 'TV Box' PC from Win 10 to Win 7, today, as it kept failing the latest Win 10 update, and was running like something that runs very slowly. The TV Box PC is just running as a headless Plex server now, so the OS isn't an issue. I'll probably switch to Linux on that box, before Win 7 reaches end-of-life, or maybe even next weekend, whilst the missus is away, if I have time .

[Breelander]

Just another word of thanks to Breelander, following the advice on Windows 10 upgrades and licensing; Windows 10 upgrades from Windows 7 are still activating for free, based on my experience today...

Thanks for confirming that activation on an upgrade still works today. That's useful to know and saves me the bother of testing with my last remaining 'virgin' Win7 machine. I have just the one shot at testing this, I can now save that for later use.