That's the trouble with owning a TARDIS, I've just returned from 2075 and everyone uses Windows 24 there.
Looking through my old discs, I came across a Word 2000 disc ( which I do know is not what I need) and I can only assume that some numbers lodged in my brain somewhere.
Put it down to old age.
I do have a old start-up disc somewhere,(could be Windows 7), but I'm pleased you mentioned the dangers of installing things when you don't know what you're doing, so I won't.
Thanks for your help anyway.