Out of the blue I could no longer access files on CD's. Somehow the drive was still accessible by certain programs, which required the presence of a CD but I could not view files in Explorer and in file dialog boxes. A gateway response email informed me I should change in the device manager, the setting on my secondary IDE controller to PIO only from DMA. I can guess that direct memory access is faster than PIO, but what is PIO (P... Input/Output)? Still waiting for Gateway's response on how this would happen and what I might do to correct the error (other than operating at a lower speed).