try cleaning first your RAMs.. tsaka dapat parepareho lang sila ng speed.. use your pencil eraser to clean the chip ng ram (yung yellow) burahin mo yun, you'll notice mawawala yung mga parang nakadikit na kalawang or corrosion dun.. or baka naman sira na yung isa sa mga ram mo, try inserting 2 of it basta yung iba iba dapat ang order nila.. if hindi gumana you might well also consider it testing your RAMs to other PCs.. if it doesnt work, its the ram, if it works, its the way how you put your ram on your motherboard, or it is your motherboard's memory slots that has the problem..