I've upgraded my memory in my Pack Bell laptop according to manufacturers guidelines and now my machine just blue screens. If I take the memory out and leave my original memory in it works fine. I had 256mb of PC2700 DDR 333MHZ and I bought another 512mb of PC2700 DDR 333MHZ The BIOS sees my memory but it continually blue screens. The blue screen error is as follows: The problem seems to be caused by the following file: ACPI.sys PAGE FAULT IN NONPAGED AREA *** STOP: 0x00000050 (0x88BF02C1, 0x00000000, 0xF7BB6DIB, 0x00000000) ACPI.sys - Address F7BB6DIB BASE AT F7BA3000, DATESTAMP 41107d27 Can anybody help me. Cheers.