there are a few reasons why a computer may use PIO instead of DMA, particularly when it's the hard disk port that falls back, not a CD/DVD drive port. For example, David Duberman reported in 2005 that some Dell computers have DMA disabled in their BIOS by default for the second hard disk. So it is a good idea to check the BIOS settings first.
A not so rare hardware problem is a bad
or too long IDE data cable. You need 80-wire cables, not the older ones with only 40 wires. With poor cables the device may work, but Windows will probably step down to lower DMA speeds or even to PIO.
..it does not matter if the cable is flat ribbon style or round
A further cause may be waking from standby mode, if one of the involved components does not perform this process correctly.
there is a script here
that you could try also...copy and paste the script into notepad...click on file...save as...name it reset dma.vbs then the arrow click on all files...should look like the screenshots...if it comes out like reset dma.txt it will not work
Edited by happyrck, 16 January 2008 - 07:29 PM.