how many sticks of memory do you have? what kind? what slots?
First, make sure your memory is compatible. I found this out the hard way.
Second, make sure your memory is seated appropriately. If you have one stick in slot 1, the second needs to be in slot 3. Same if you have a stick in slot 2, the next must be in slot 4.
i fiiiinally got it solved...turns out it was the cpu cuz xfx upgraded the bios and was no longer
compatible with the pentium D line so i bought a core 2 and it works fone