You don't own your Windows install, you own a licence to it.
That all depends on which country you are in. In Australia, software is a product that you own, not a licence that you own.
Also, given that the EULA only pops up after I have paid my money for the product, this renders the EULA invalid under Australian consumer law, as you cannot impose extra terms and conditions after the point of sale.
What really interests me though is "the supported lifetime of the product". Given most of the regulars here are technically based folks, odds on at least 90% of us are supporting at least one device that went end-of-life with the manufacturer years ago, but that does not stop us from supporting it.
Companies and their lawyers like playing semantics, lets see how well they go when end users start playing semantics back at them.