Change only motherboard, CPU and Ram??

Yeah, "shrink wrap" EULAs are pretty much a thing of the past - thanks to downloads and trial periods. For those unaware, what used happen several years ago when all software came on disks purchased at a store, software makers would put the license agreements inside the shrink wrapped packaging. You had to break the seal of the packaging and open the box to read the EULA.

The "catch" was, one of the terms of the EULA said if you break the seal and open the packaging, you agreed (as in a done deal) to the terms of EULA, whether you ended up liking the product or not. If you went for a refund because the product did not work or did not meet your needs, you probably would not get it because the package was opened. Catch 22.

Consumers were left in the lurch for a long time on this - thanks in part to the rampant illegal copying of music and software already going on. Fledgling software companies were being pirated to death. Big companies were taking HUGE losses in profits resulting is HUGE losses in tax revenue for governments. But honest consumers were being punished. That's typical of life I guess but still not fair, and the courts agreed.

Now EULAs say (or should say) that you agree to the EULA when you install, or decide to use the product. Because the Internet makes it easy for developers to demonstrate and distribute their products, and it makes it easy for consumers to research and try software before buying, most reputable software makers put trial versions and demos on line, and the EULAs too. If you don't see a EULA, use the contact us links and ask. If no response, or you don't like the response, seek a competitive product.

I posted this on page one, but here's the link to Microsoft's EULA "wizard" for virtually all their products. Sadly, the wording for the options as to how you acquired the software is a bit flaky.

Option 1 - From a store as packaged software for end-users or Microsoft directly? "End-users" and "packaged" are the key words. Both imply full "Retail" versions.

Option 2 - Pre-installed on your computer from the computer manufacturer? This is OEM/System Builders. As a reminder, the software industry - or rather their lawyers see "self-builders" as computer manufacturers, not "end-users ". This leads back to the manufacturer being required by the terms of the OEM EULA to provide 1 year's of technical support for the product. You as the maker (or maintainer) get the software at a cheaper (wholesale) price but in turn, you must provide any support to your "client" or "customer" - even though that client or customer is you. ​

The ONLY way you can have Windows installed legally on multiple computers at the same time, regardless whether a OEM or retail license, is if you have some version of a "volume" license. And it will clearly say the number of computers that license supports. I've been dealing with Windows licenses for many years and I have never seen a 4-pack license. Note on your link to Newegg, the 1-pack, 3-pack, and 30-pack offerings.

If you have a typical 1-pack "Retail" version, you can install it over and over again on as many computers as you want - AS LONG AS you uninstall it from all previous computers before installing on a new. That is, you can install it as often as you want, but it can be installed only on one computer at a time.

If you have a 1-pack OEM/System Builders license, you can install it over and over again, but only on the same computer with the same motherboard.

Now "activations" are different. You can activate your copy of Windows over and over again too. Eventually, it may trigger the need to actually talk to a MS rep, but all you have to do is tell the truth and make sure it is only installed on one machine, and if OEM, the original machine. Activations can be triggered by several things. Usually you can swap out graphics cards, RAMs, CPUs, optical drives several times each and not trigger a reactivation. But if you swapped them all out at once, or swapped out the boot drive or motherboard, it likely would as Windows would see so many device changes at one time, perhaps suggesting the same license is being used on two computers. That is where the "4" might have come in. Some use to say you could change out 4 pieces of hardware before a reactivation was triggered. I think that's just a rumor, or maybe an average because I know a new motherboard and HD will trigger it. So I think it goes by devices, and weighs different devices differently too.

Activating Windows FAQ