Hi johnoh,

there's a couple of ways you could test your memory. You do the above (I'll explain how shortly) or you could try using memtest, this is a free utility which does what it says.. A guide to using memtest and download is here:
Tutorial: How to use Memtest - TechSpot OpenBoards

The method posted by Asta assumes you have two sticks of RAM one of which may be faulty. To determine which, involves just using one stick at a time and trying to replicate the fault. If the error happens with one stick and not the other then you know which stick is the bad one.

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