... 16 GB of cached MN pages.
He had to take my hard disk into his work (he's an IT geek) and delete them all. Took him 6 hours.
He has been sniggering at me all day.
Not helped by my throwing a hissy fit at the weekend and insisting that we had to get a new computer as mine was unacceptably slow. It seems to be working a bit better now