Thanks anyway Peter.
I know it would probably speed things up a bit....though I do use things like CCleaner regularly.
I suppose since the thing has worked pretty trouble-free for years - loathe to mess with it.
A few years back I was always playing about with the BIOS and fiddling with other inner workings of my PCs, but you soon forget when you haven't NEEDED to for a while. Maybe I'll just let sleeping dogs lie until I want to update to a later Windows...unless Les can talk me through it.
I do have another operating system downloaded to one of my other hard drives, in case of emergencies (Ubuntu).