The saga continues....
Even CurrysPCWorldDigitalDixonsComet's resident computer guru couldn't get the laptop to work acceptably with Win10 'anniversary' and all its updates, so he contacted the head office and they've agreed to exchange it.
So I'll be getting a 11.6" laptop with RAM extension from 2GB to 8GB and a 64GB SD card to eliminate the need to store anything much on the C-drive. Plus Antivirus, Windows 365 and an extended warranty. With all the current promotions, plus a pro rata refund for the unused part of the extended care plan for the old laptop, in the end I'll probably be up about £5 on the whole deal...
(Apart from the cost of the petrol used for 7 visits to the store, that is!)
I was due to collect it today once they'd done the RAM extension, but they rang to apologise and told me that the wrong type had been sent - the laptop has a single layer RAM slot and the extension module was 2 x 4GB. So I could either have it today with 1 x 4GB, or wait until the middle of next week for a single layer 8GB module. I've chosen the latter option.
Hope it'll be worth the wait though!