I decided I wanted to run Zwift on a larger screened laptop than I gad, so bought a cosmetically challenged ex-display Acer 17" one, from eBay.
When I received it, it was without a note of the password (I asked, and received it later), no worries, I reset Win10, and put in my own info. Downloaded Zwift, and it immediately starts to update. Then fails with the message "error Z117 at page 602..." etc. This, apparently, means Zwift is having trouble writing to the Documents folder, because reasons, none of which I believe apply as it's the only piece of software other than Win10 Enterprise that's on the bloody thing and I'm deffo the admin. Gah!
One of the workarounds was to run the installer as admin - which indeed starts the programme, but - why? Bloody nuisance to have to do that every time.
I'll try another clean install, this time I'll opt to clean the disk (125Gb SSD) as well, and see what that brings.
ETA: Well that worked, fortunately there was nothing I wanted on it, not an option for someone wanting to start using Zwift on a machine they already had.