Ashiq_Ahamed, you have 2 different types of memory. The 12800R memory is registered (buffered), and the 10600E memory is unbuffered.
Early versions of the Z600 only suppport unbuffered memory, later versions (with the later BIOS boot block date) support both unbuffered and registered memory. However, do not mix differnet types of memory. The system will not boot with different types installed, use one type only.
