For some reason, the first 64k of RAM is not responding to the CPU. The memory chips may be bad; you can try switching the high and low memory on you motherboard to see if the problem goes away. In any machine now a days the first bank of memory contains the first 64k (or the first 256k is the computer is using 256k chips and so on and so forth), so switching the first and second banks(or the third or fourth banks) may solve the problem. Read you PC's instruction manual to find out which is the first bank on your particular motherboard. A motherboard can also cause this problem. If the memory chips all test good, you will have to replace the motherboard itself. Return to the main menu.