For what it's worth I've just got a new notebook with Windows 10 on it.
Previous notebook runs Vista but is 32-bit, I use iTunes a lot and the latest version of iTunes is now 64-bit, so of course it wouldn't update anymore.
This was OK for a few weeks until the last time I synced my iPhone with it (As I would normally do) and in the process got an updated OS for iPhone.
When iPhone rebooted it then says "can't connect to iTunes, it's too old" !
There are a few other things as well, for example I've been using Firefox for a few months as Internet Explorer stopped updating past version 9 point something. Then Google maps was all redesigned, which won't work in IE9, does in Firefox BUT quickly runs out of memory until the street view scenes go black.
I knew that a new machine was on the cards sooner or later, so finally bit the bullet, and also got a new wireless router which is brilliant, no more annoying cables and the Vista machine and the iPhone can use it as well!
Bottom line is the Vista machine is/was a 2007 model, in the computer world that makes it ancient.
Getting used to Win10, much of it I was pleased to see is much like Vista. I've also seen systems settings windows that look like they haven't changed since Windows 95.
I have a number of old programs (meaning, 20 years old), and got them to run, although the installation set-up refused to work. Was easy to et around though, as nearly all the program files are in one directory, simply a case of copying the folder from Vista onto Win10. There's a very few system files under Windows foldlers, and turns out Win10 has got most of them already, so didn't take long to get them running. Ther program compatibility wizard seems quite sophisitcated so a case of let then chew on it a bit and figure out what 'shell' to run it in, which can go back to XP.
Fortunately these old progs are 32-bit so the OS can run them.
Generally it's all pretty slick, as it has a 2-core Intel i5 CPU which can run 4 threads simultaneously.
Still using Firefox as I like its add-ons and stuff, but coming with Win10 of course I also got MS Edge AND IE11.
It also has a PDF print-to-file driver, which is well handy as on previous machines I installed Docudesk print2PDF to do it. (I use it for work generating order forms and invoices that I can then send by fax or email.)
Windows 10 Mail on the face of it seems totally pants, UNTIL you realise, as I did, that you need to create an email account at outlook.com, THEN it all makes sense because THAT is where you can make new folders, routing rules and spam filters, and do all the other maintenance type stuff, using a web browser, because Win10 Mail is just a 'Window' onto your outlook email account, and with seriously reduced functionality compared to using the web pages direct.
If you have another web based email account that can do that and be accessed by Win10 Mail then fine, my problem was my primary email account is my ISP's, which unfortunately is totally non-editable online.