In Windows XP, DMA is not set for single Hard Drives and Optical Drives. In its place, Direct Memory Access is set for the Primary IDE Channel and the Secondary IDE Channel. In other word, every IDE Channel permits you to have two devices attached for a total of four IDE devices. Therefore, if both channels are set for DMA access, then all the channel devices in your system will be set to use DMA.
Go to start >> control panel >> system >> double click on it
Open the Device Manager>>choose the Hardware tab, and then choose Device Manager.
Open IDE ATA/ATAPI Controllers" option and double-click on "Primary IDE Channel".
Under the "Advanced Settings" tab, check the "Device 1" setting.
Set it to "DMA if available".
Do again the step for the "Secondary IDE Channel" if you have devices connected to it.
Restart your computer.