ARCHIVED: In Windows, how do I enable or disable Direct Memory Access (DMA)?

DMA is a way of sending instructions to a PC's memory. Your PC has DMA channels that bypass the CPU, keeping it free to do other things. Like Interrupt Request Numbers (IRQs), DMA channels are limited and allocated to only one device at a time. Therefore, DMA conflicts can arise which may make it necessary to disable DMA on one or more of your devices. To do this, follow the steps below:

To enable or disable DMA in Windows 2000 or XP:

1. From the Start menu, select either Control Panel, or Settings and then Control Panel.
   
   
2. Click the System icon and then click the Hardware tab.
   
   
3. Click the Device Manager button.
   
   
4. Select IDE ATA/ATAPI Controllers.
   
   
5. Right-click the Primary IDE Channel icon, and select Properties.
   
   
6. Click the Advanced Settings tab and select or deselect DMA from the drop-down menu. Click OK.

To enable or disable DMA in Windows 95, 98, or Me:

1. From the Start menu, select Settings, then Control Panel.
   
   
2. Double-click the System icon and click the Device Manager tab.
   
   
3. Click the + (plus sign) next to the device you would like to change.
   
   
4. Select the device you want to change, and then click the Properties button.
   
   
5. Click the Settings tab and select or deselect the DMA checkbox. Click OK.

Note: If problems persist, you might also need to disable DMA in your BIOS settings. You should not attempt changes to the BIOS settings unless you are an experienced user. If there is a setting in your BIOS to enable and disable DMA, you can usually find it in an area such as "Advanced Chipset Settings". You may need to contact the vendor of your system to find out if and where your system BIOS has this setting.