Well, I've run all those programs, thanks, Milo. Not sure if everything's back to normal, but we seem to be getting there!
The weird thing I'm noticing now is that some sites are responding normally on Internet Explorer, and others are hanging as before. For example, PPrune works for about a second and then refuses to respond, whereas a camping site called myswag.org works perfectly.
Windows sometimes pops up a thing with 'Internet Explorer is not responding', and in 'problem details', says 'A problem caused this program to stop interacting with windows.' Problem Event Name is given as AppHangB1.
I don't know, getting a bit discouraged now but will come back to it later after I've thought about it more. Bloody computers!
Thanks yet again, Milo. You've been a great help.