SMORIZIO thanks for your help, I pulled out all the ram tested it individually it all worked
then I reinserted ram firstly into red slots ( 2 sticks ) and then black slots (2 sticks ) turn pc back on
and all ram is now present.
Strange thing is I pulled out the ram yesterday and switched it around but it didn't solve the problem but today is all good ??
only thing I done different is place ram as pairs in each colour slot.
My bios is still 2104 don't think I will update it as im not comfortable with that process in the past I used auto update but now that software is not compatible with this op system.