It really is an investment in time to get everything working again and now that one can not just plonk in a spare drive, I'm starting to think the small sum for a second PC is probably worth it. I was going to offload the i5 dual core once the quad was commissioned, but not now. It can just come out for updating and backups. I'm not sure if a laptop would qualify for this job as they are A/ More valuable by far. B/Not as fixable. C/Not possible to fit a huge ('Red' for example) drive for backup. I know little about long-life 2.5" drives.
Yes, I was surprised one needed cortana for Windows to function so not possible to zap it altogether. I do turn everything off however, which happily leaves the box for searching. It seems possible to turn any item back on if needed.
I've created a restore point called 'Microsoft Edge only' which is also auto-dated and timed. Next one will hopefully be 'Firefox and Office' etc., etc.
But still I'm risking everything on one drive - fast as it is. (25 seconds from pressing the power button to active desktop.) I know they meld Apps with the OS but while having the full un-installed copy on another partition buys some insurance, there's nothing like having a separate boot drive which can also back up top priority files. One remote drive as well and One can start to breath easy.