Originally W10 upgrade on W7 - that fell over after about a month.

A clean ground up install isn't much better...................

When W10 imploded - I couldn't repair, re-install or anything. The only cure
was to overwrite the HDD by installing Linux, then clear all that out and
start over with W10.

Pretty much every application starts off; "not responding", the HDD activity
light is busy almost all the time. The cursor frequently changes from an
arrow to a little blue circle, either way the response is usually hesitant -
if it gets around to moving at all.....................

It was tolerable when I was using freeAVG, someone told me that was the
cause of the problems and I should switch to Avira - I did that and now the
PC is pretty much unuseable.

When I tried to go back to AVG, the installation failed, so it looks like
I'm stuck with Avira.

Thanks for any help.