[Brightcolours]

 ........  so what's changed all of a sudden that I'm risking ??

You risk your computer getting hijacked/infected/taken hostage by a boat-load of discovered security flaws that have been left unpatched since Windows 7 update support was basically dropped. Of course, using Windows 10 does not make you immune to new types of attacks, but it limits the scope of discovered flaws quite a bit.

I am at risk using my macs too, as this guy from Microsoft security support keeps calling me to tell me that my computer is infected. Regrettably I never find out what to do about it, as I am quite allergic to his thick Indian/Pakistani accent/dialect so I hang up before they can help me.

As I wrote above, you can simply put in a USB3 card in your computer like this:
https://www.amazon.fr/Cuifati-Adaptateur-dextension-linterface-Windows8-1/dp/B08GQ5RL6P/ref=sr_1_2_sspa?__mk_fr_FR=%C3%85M%C3%85%C5%BD%C3%95%C3%91&dchild=1&keywords=USB+3.0+PCI+Express+Card%2C+windows+7&qid=1620207461&s=computers&sr=1-2-spons&psc=1&smid=A2OUWHX00DW2XC&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUExRTNISzJIS0NWQ05MJmVuY3J5cHRlZElkPUEwMTA5MDcxM0pMTlpMSlFWUk5MRCZlbmNyeXB0ZWRBZElkPUExMDE5NTg3MzBBOVcxUks2VzdUNCZ3aWRnZXROYW1lPXNwX2F0ZiZhY3Rpb249Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU=

That will bypass your firmware-caused lack of USB 3-ness.