Hey all and many thanks for your answer...My system say i have 2 GM memory, but I think I maybe now know what the problem is from what you have told me. I had 2 x 512 MB in my motherboard in my pc, and bought 1 x GB memory more. But as I can read from your answer, its because i DON'T have 2 x 1 GB memory, insted of 3 diff. memory sizy....Is that correct ?? They are all PC3200 DDR400 moduls. I dont overclock anything, and the settings in bios for my memory is set to auto. Sorry for not to mension it was 3 moduls I had in my first message !!! Le Baker