[Hampshire] [OT] All sorts of hardware issues

Hi all

Does anyone know of a cost effective solution to a "dirty" electricity
supply? My father-in-law's PC (built by my own fair hand admittedly!) is
having all sorts of hardware issues and I don't think it's my workmanship -
I think it's the electricity supply at his house. In 2 years, we've had to
replace 3 hard drives, 1 power supply, 1 router and now his optical drive is
only working intermittantly. Admittedly he does faff about installing
stuff not having a clue what he's doing - but the errors he comes to me with
are so serious I can't believe he's doing this himself.

I'm thinking that a standard surge protector isn't good enough - it's not
power outages that are the problem - I suspect it's blowing components
because (if we were to test the AC at his house on an oscilloscope) we
wouldn't get a nice sine wave.
My electronics knowledge is very rusty though. Are we talking another
surge protector, a UPS - or something more fundamental here?

Cheers
Rob