Control Panel > System > Hardware Tab > Device Manager > IDE">

Pro Audio Support

Q:
To enable DMA for Hard Drive in Windows XP.
 
A:
It seems the default is already set to "DMA if available".Start menu > Control Panel > System > Hardware Tab > Device Manager > IDE ATA/ATAPI Controllers > Primary IDE > Primary IDE Channel (for 1st HD) or Seconday IDE Channel (for 2nd HD) > Advanced Settings > Device 0 > Transfer Mode > Set to" DMA if available".