extra memory casuing startup issue

Thanks for confirming my suspicions. My only problem now is to locate the right item to alter in the bios as there is nothing obvious. I hope that updating the bios may help to clarify that. I'll let you know when I have done it - but it wont be for a day or two as my daughter is moving house from tomorrow so I shall be rather busy with that.

SOLVED. After going and checking bios updates for the m/b I discovered that for this particular bios chip there was a known issues specifically covering my problem. Updating the bios has now solved this issue but it did cause another problem but I shall post that in another post called "What went wrong?"

Thanks guys for all the help and suggestions.