Hello. chatmoca,Welcome to the forum. Does your drive go into PIO Mode after you change it to DMA? If so you have got some conflicts. The computer registry if it is screwed up will cause the OS to Downgrade from DMA to Pio. Download a free registry cleaner and clean the registry.Are all of the cables seated properly? I am almost willing to bet it is a conflict in the registry so I would do a cleaning of the regisrty first and you can Google for a free one. Most here use CCleaner