I had two pc's desktops,together some years ago and one monitor.If I wanted to change I had a switch thingy connected and just hit a button and it changed pc's.I'm sure that they improved their connections and this is just an idea that might solve your problem,Win on one and Linux on the other.
You aren't the only one that see's the obvious.

IME old games generally work better on Linux than they do on Windows. I've had to give my sister a USB stick running Linux in order to play some Windows games that don't run well on Windows...

That said, if an old game really does run better on Windows, then perhaps it won't be too demanding and you can run that in a VM. Right now, I don't think you need a license for that (when the installer asks for license key, you can skip it and install & boot just fine; it occassionally nags about the lack of activation but apart from that, works just fine).

As for old games with copy protection, I'm afraid you have to hunt down cracks for the ones that don't work ootb.

In any case, I'd rather spend that money on better hardware (or save it). Windows, not worth it. I only have windows on my laptop because it came with windows pre-installed, but I haven't booted it in a couple years or so.

Oh yeah, regarding cheap license key resellers.. you're right that's shady stuff. The keys may be legit, but the reselling probably isn't, and if it comes to light, Microsoft can (and they have in the past) blacklist these keys. As a matter of fact, my sister had one of these keys.. and it worked fine for a couple years. Then it didn't, and we had to figure out why :-)

Well as long as one know what one is doing it should be ok....I was more trying to make people aware that one needs to be careful when using such things. :)

I've tried W10 and all the fixes only solve half the problem though:-

1. MS can and does re-enable stuff during updates (which unlike W7 are now forced for consumers). Even when you get things right, the OS is so unstable from one year to the next that it's ended up the most "high maintenance" Windows in recent existence for keeping on top of ever changing hacks & workarounds. About the only usable version is Enterprise LTSC whose feature is it doesn't receive MS's half-broken bi-annual "feature" updates. Of course it's not available for consumers.

2. Half the telemetry stuff is hard-coded into the OS, eg, MS Telemetry will completely ignore any attempt to block IP addresses of MS servers via the OS's own firewall or Hosts file. The only way of "hard blocking" it for real is using a second non W10 device, eg, router firewall, or a second PC or "pi hole" used as a gateway / proxy. And then W10 goes berserk and starts making literally thousands of connection attempts per day. Some have even reported it starts to deactivate and show the unactivated watermark.

3. GPEdit has a lot of settings that will "appear" to work in Home / Pro but are only actually functional in Enterprise / Education. Eg, MS removed the ability for W10 Pro users to properly disable the Windows Store. "Turn off spotlight", "Don't search the web or display web results" (Cortana) are Enterprise only settings. And "disabling" Cortana still has the related Search.exe running in the background. Likewise you can set Telemetry to 0 but as GPEdit says itself, if you're running Home or Pro it'll be ignored and treated as a 1.

Personally I hated it enough that I went from W7 to W10 to dual-booting W7 + Linux Mint.

That's not how open source works at all. A similar situation happened to OpenOffice, and it just "forked" off into LibreOffice which is now the better product.

well i disabledthe windows store and im on w10 pro 64, ive locked down my pc hard so that i cant use any browser on my pc (edge and IE) for personal reaosns and used the registry and gpedit to lock certain settings so my pc is basically a games console now.

also if you are on windows 10 i reccomend getting shutup10 and ribbon disabler as it gets rid of that awful explorer bar and replaces it with the windows 7 one, also if you dnt like w10 start menu you can always get classic shell and have windows xp,vista or 7 start menu style, i spent alot of time configuring my pc and ive had 0 issues with my pc

So, my plan has not really changed since I started thinking of getting a new computer (https://www.gog.com/forum/general/new_desktop_computer_custom_build) but I wanted to write it down to crystallise my thoughts yet once more and maybe get a discussion going as there must be a lot of people in a similar boat to me.

My solution:
Linux and only that on the new computer. Not sure yet what to do with the old one except my plan was to rob it of some parts.

You, whoever you might be, should choose what suits you best.

For gaming, I went back to Windows as Wine was a very mixed bag when running older games most of them being on GOG. The updates to Wine would break some things but then make some things playable. I only wanted one version of Wine instead of my system being cluttered and having my games be portable so PlayOnLinux took no liking to that.

As far as Linux goes for other things like watching videos, it's gotten really good. I'm currently trying Antergos on a laptop and having very minor issues on it with the integrated graphics but other than that I have learned a lot and it runs very stellar for someone who is new to Linux. It teaches you a lot too about Linux in general. I recommend it for people who are new and like to tinker.

For those just looking to game, I would just clean install Windows 10 Pro and get the Shut Up Windows 10 program. I personally went with W10 Privacy program which blocks out the telemetry and I also think it disable the mandatory Windows updates. It's like a deep cleaning for Windows 10 and it's open source but starting out with Windows 10 Pro with a clean install is definitely an advantage either way. Shut Up Windows 10 might be more user friendly but either way, it should work.

Linus Tech Tips also has a good guide on how to make Windows 10 more privacy oriented or more like Windows 7, which I used when I first started but it is more of a manual process. I avoided the aesthetics portions of it except for the start menu so it was actually pretty simple rather than the wall of text it is. You could do a search for Windows 9 Linus Tech Tips on YouTube or the forum and most likely find it on one or the other at least. Very useful guide but I think the programs do the same thing but more quickly since the guide is more of a manual process. That's why now I use the W10 Privacy program. This guide does help explain exactly how and why the changes are made in case anyone is curious.

Edit: You could search for the Linus Tech Tips guide on their forum, is what I meant.

Umm... Just get the USB version of windows it already comes with it's own key

If you want some advice from a "Linux newb" who's been with Microsoft since MS-DOS 2.0, I found it helpful to introduce it in stages. Years ago I think I tested something like SUSE 6 and it didn't work out at all, Linux as a Windows replacement was primitive plus it was "too much change at once" trying to completely wipe Windows + all applications at once. This time around, the first stage I didn't install Linux at all but rather installed (on Windows) and got familiarized with every major cross-platform software I could find (LibreOffice, GIMP, Darktable, Dia, Openshot, etc, was already using Firefox, Thunderbird, Audacity, Inkscape, VLC & Handbrake, etc). Then when it came to install Linux, the learning curve and expectation of things being different was greatly reduced as it meant I could focus on the OS and not have to relearn the apps at the same time plus the OS itself already felt like it had a greater sense of familiarity.

The logic was also "even if Linux didn't work out, for a fairly low requirement home user the 'need' to keep rebuying office / photo software every few years is long over and I'll benefit on Windows anyway" (ie, even on Windows I benefited from stepping outside the MS Office / Adobe downward spiral rat-race towards 'renting' everything). I'm dual-booting because Linux isn't perfect as a gaming rig (some games can be finicky, others that work may get slower fps, etc), but overall Linux Mint was a lot more pleasant and BS-free than I expected and is heading in the right direction in all the areas where Windows 10 in heading in the wrong one with attempted "servicification" of everything. Good luck, and I hope it works out for you. :-)

Edit : I should also add that as ThorChild mentioned below, it is actually possible to run W7 on modern Coffee Lake & Ryzen's. The APU's won't work, so you'll need an AMD / nVidia GPU, but if you have one, then there are chipsets and motherboards that are W7 compatible. I wrote about this before in-depth here:-

https://www.gog.com/forum/general/skylake_users_given_18_months_to_upgrade_to_windows_10/post119

It's a difficult dilema for a gamer for sure.

Just last week i built a new Ryzen 5 1600 build that i had been planning for a year or so now (RAM was too expensive etc). These are the specs:

CPU: Ryzen 5 1600 (it was on a 45 discount!)
RAM: 16GB Corsair Vengence 3000Mhz (just 80.00!)
MOBO: MSI 450I m-iTX form factor
Case: Core 500 m-iTX
PSU: 550W Gold Seasonic
SSD: 500GB Samsung 860 EVO
GPU: currently my old 750Ti while i figure out what 1660/1660Ti to buy.

So all that is fairly recent hardware, and here is the thing i fully intend to run Windows 7 on it, which specifically meant i looked for hardware that would be possible on. The most important being the mobo and CPU. There has been a trend from MS and Intel (and AMD!) to 'lock' their newest hardware to Windows 10, and that just won't do for me. I've drawn a hardline in the sand over Windows 10 and will never buy/use it.

The system above will work on Windows 7 and the final build will be a dual-boot Windows 7 (for games) and Linux Mint format. I had considered running Windows 7 in a VM under Linux Mint, but as with stuff like Wine, you can never be sure just how well that will work. I have a lot of games (here and from my lifetime of gaming (lots of CD/DVD's!)) and want as compatible an environment as possible, so dual-boot is the best way to acheive that.

As for future games and Windows 7, in truth i don't look forward (or play) the latest AAA games as i find them, 90% of the time, shallow and not as deep and interesting as older games in their genre's. I still play Civ IV as my 'best' version of Civ for example, and that pattern is repeated across many, many games.

So i doubt there is going to be something i will really feel I am missing out on, the modern games industry is what it is, has identified it's market and how to milk it, and it is not why i ever was interested in games in the first place, so i don't loose any sweat over it.

Having said that IF it turns out Cyberpunk 2077 will not run on Windows 7 AT ALL, that might be an exception to the rule, but it is just one game, out of the many thousands i have available to me. It would probably make me want to hit up my Amiga emulator and run B.A.T or Captive/Liberation! ;)

If you know 100% the hardware won't run Windows 7 (because it has been blocked from doing so), well you are a bit stuck, so i would adivse to just buy hardware you know can work with the best Windows OS ever made.

also an issue is when MS phase out DX9 and 11, then people will be forced on t owindows10 cos th at offers DX12 for cards that support it anyways

It should also be noted, that Education edition has pretty much the same features as Enterprise. It is often available to students for free (which is how I got mine a few years back) and you can disable same stuff like in Enterprise (like setting telemetry to 0, not being forced to install updates etc.). But yes, they are unfortunately not available normally.

Another option is to get a win7 key and do a free upgrade to win10, this can be 100% legit and I´ve done lit ots of times. Some pc's have a win7 key on the case that can be used to activate win10, I have loads of old pc cases.

However, I don't use win10 whenever possible. Best M$ OS imho is by far win8.1 with classic shell (instalLs a win7 style menu). Even radeon software now installs and work properly on win8.1.

I have a Win7 retail key but when looking at MS' website it says the free upgrade has gone and is no more.

Maybe the online upgrade is, but MS still allows you to download their Media Creation Tool and use it to make your own installation media for Windows 10 and after the installation you can activate the OS with Windows 7 and 8.1 keys.