DMA Reverts to PIO

run REGEDIT. Go to the following key:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4D36E96A-E325-11CE-BFC1-08002BE10318}\0001

if your disk is on primary IDE channel, or the same, ending with \0002 for

the secondary channel.

Delete MasterIdDataChecksum or SlaveIdDataChecksum and MasterDeviceTimingMode* or SlaveDeviceTimingMode*. Reboot. The drive DMA capabilities will be redetected.