[Hampshire] Is a faulty download to blame for my problems?

Ever since I installed Etch, because I was beginning to be constrained by
Libranet 3 and was starting to have problems, I have been having one problem
after another. The latest appears to be completely intractable, and to
prevent me from solving any of the others.

So the question inevitably arrises: software or hardware? I have run
smartctl (thanks, Vic and Chris :-) ) on the HDD holding the installation
and it reported that there were no errors. I have run Memtest for a while,
which also reported no errors, and I have swapped my IDE channels over. All
passed the test. But something, somewhere, is obviously actually faulty.

Is it - however remotely - possible that my install of Etch (I used the net
install facility) is itself faulty? Is the most sensible thing to do to
reinstall Etch on the present HDD? Or to install Etch on a brand new HDD?
(I have a brand new HDD because the HDD I was originally trying to install on
_was_ faulty, and Western Digital replaced it under guarantee.) Or should I
have recourse to a fresh install of Libranet 3? It is a bit long in the
tooth now, but then so are both I and my machine. Or should I install
something completely different? Perhaps even leave my comfort zone and come
to grips with rpm?

Advice, please! This is my main desktop. I need to have it working.

TIA
Lisi