The problem started with a delay write error to my USB hard Drives (1tb and 3 500GB drives - all failing). On restart they would be fine but as time progressed they would fail again. Then once they had failed and I'd kept the computer on they decided to fix themselves and work for a time being before failing again. When this happened the Lan connection suddenly started dropping out (wired line).
I tested the USB devices and my Lan connection (using the same wires) on my laptop - all fine.
I then went into the components taking them out one at a time to see if anything was causing the issue (Sound Blaster Audigy, Graphics Card). The problems kept occuring on rebooting my machine when these devices were out of the machine.
Then I came to the memory, I have two 2GB sticks and there are four memory slots on my Motherboard. I started by taking one out. On restarting all the problems had vanished and I assumed I had found the culprit. Then, after a week running on the same component configeration the USB and Lan problems came back. I then swapped that stick out for the one I'd taken out previously, again the machine ran perfectly for more or less a week before the problems started again. I then put both sticks back in to their old slots when the machine was really bad at the start of this whole process and everything was fine - again this only lasted for a week before the USB and Lan issues came back with a vengence. Every time I move the memory about it fixes the issues for about a week. I have tested the memory using Memtest and it's fine. Is this a Motherboard issue or an OS issue? Thanks, Ben.