Well, I went to collect my laptop from CurrysPCWorldDigitalDixonsComet today after its repair.....
To find that the operating system had been corrupted. But as well as updating the BIOS, they'd rolled back the OS to the original Win 8.1 state of over 2 years ago...
It was also covered in greasy finger prints and marks where they'd attached repair stickers. Whereas when I handed it in, it was in as new condition.
I refused to accept it until they've restored the current 'anniversary' version of Win 10 - they also said that if I wanted them to restore MS Office, they would charge me £35 even though the system is under extended warranty until July 2019...