1. Go to the Device Manager. For that, click the Start button and then click Settings, Control Panel.
Then, in the Control Panel, double-click System.
Alternatively - right-click the My Computer icon on the desktop and then click Properties.
In the System Properties window, select the Hardware tab and then click the Device Manager button.
2. In the Device Manager, expand the IDE ATA/ATAPI controllers entry, either by double-clicking IDE ATA/ATAPI controllers or by clicking on the + next to it.
3. Select the appropriate IDE channel (Primary or Secondary). To get to the IDE Channel Properties window, either right-click the channel and then click Properties, or select the channel and click Action -> Properties in the menubar.
4. In the Primary/Secondary IDE Channel Properties window, select the Advanced Settings tab (if the Properties window does not have an Advanced Settings tab, see the Note at the end).
5. Choose either the Device 0 frame for the master device on the channel or the Device 1 frame for the slave device on the channel, depending on whether the drive for which you are trying to enable DMA is master or slave. Click the Transfer Mode pull-down menu. Select DMA if available. Then click OK.
6. You will now be prompted to Reboot. Do it.
7. To verify that DMA was indeed enabled for the drive, repeat steps 1-4 to open the Advanced Settings tab of the IDE Channel Properties window. The Current Transfer Mode box should display Ultra DMA Mode 2 if the drive can handle this, or Multi-Word DMA Mode 2 if the drive does not support UDMA. If DMA was not enabled, it will say PIO Mode.
Here is an example of how the IDE Channel Properties window should look like. In this example, two optical drives are connected to the secondary IDE channel. The master drive supports UDMA33 and thus is in Ultra DMA Mode 2, the slave does not have DMA enabled, so it is in PIO Mode
Note: With some IDE drivers/Busmastering drivers, DMA cannot be enabled through the device manager, but only through the driver settings. An example of this is the Intel Application Accelerator.
