I have a HP 6640c pavillion- it came with 64 MB RAM- I ran my programs OK- with mediocre performance. I recently bought 3 128 Mb chips- the day I installed the new RAM - my computer has not been the same. performance is the same and seems even worse than when i had just the 64MB in it. the original chip was pc100 - alll the new chips are PC 100 - what could the problem be? SOmetimes the pc doesnt even want to start up - my gaming is worse than when I just had the one chip in --WHATS UP?