Okay, I'm happy to question my chap about this build. I know he won't mind, as he has already admitted, he does not think in terms of the computer being used as a DAW when building his machines. These things were built mainly for gaming and so speed, stability and quality were his main aims. I've known the guy 20 years and he never buys any crap. He knows he is not a sound engineer (but he is a competent electronic engineer, nevertheless).
So we've got an Asus motherboard, AMD chipset, Kingston Memory, Seagate drives - all the top quality stuff. The PSU was chosen to cover consumption, so it's 750w (can't remember the exact make but not a cheap one). Plus my E-MU 0404 sound card, which seems to be an old favorite in the HR community. So I'm not really sure what part of this is done wrong. As far as I know, all of the parts in this machine would be considered more than adequate quality by all those who swear by building their machines, instead of buying 'off the shelf'.
The only thing I can suppose is that it's got some kind of virus or malware on it. But then, I had a dual core Hewllet Packard machine running before this one, which was kept off the internet - and that broke down as well. The one I built (the only one I've ever built all by myself) was out of cheap parts like a budget MSI board and a single core AMD chip with Maxtor hard drives - and that's still working. Slow as hell, but still chugging along.
So, as you can imagine... I'm not sure what to think any more.