OK thanks.
Another silly question, would i be better to look at replacing these with 4 x 2gb (something like this 8GB Memory Corsair (4x2GB DDR2 xtreme 2Rx8 PC2-6400U 800MHz 240pin) For PC ?
Does is matter what the numbers are ie:
PC2-6400 DDR2 CM2X2048-6400C5,
CM2X2048-8500C5C,
CM2X1024-8500C5 PC2-8500 DDR2-1066 1066 MHz
What is the better type?