[damien c]

sorry to say this but acer will tell you to restore it first back to factory settings incase of software fault, they will only look at it if it is a hardware fault i know this because i use to sell them for comet, and had to deal with them on a weekly basis also if you have removed the version of windows that was originally on the pc without creating the backups therefore not, being able to do a factory restore iirc then they will say you have voided your warranty because that what hp does not 100% sure about acer.

as stated above try with just 1 lot of ram and see what happens but my oppinion is software issue if some parts are still showing 3gb of ram.