Recently I have noticed lots of customers that are experiencing general slowing down with Windows XP Service Pack 2. After detailed investigation I have found that this computer no longer uses the standard DMA mode (Direct Memory Access). The strange thing is that the option to enable the DMA mode has been disabled for some reason. To check if your computer is experiencing this issue please follow these simple steps:

1. Open the Control Panel

 2. Double click on System

 3. Click on the Hardware tab

 4. Click on Device Manager button

 5. Expand IDE ATA/ATAPI Controllers

 6. Double click on Primary IDE Channel and then Advanced Settings tab. Check the current status mode.

 If your hard drive is switched to PIO mode you need to follow these steps to resolve this issue:

1. You need to open the so called registry editor:

1.1. Start Menu -> Run

1.2. type 'regedit'

2. Go to 'HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4D36E96A-E325-11CE-BFC1-08002BE10318}'

3. It has subkeys like 0000, 0001, 0002, etc. Normally 0001 is the primary IDE channel, 0002 the secondary, but other numbers can occur under certain circumstances. You have to go through these subkeys and check the DriverDesc value until you find the proper IDE channel.

4. Delete MasterIdDataChecksum or SlaveIdDataChecksum, depending on whether the device in question is attached as master or slave, but it can't actually hurt to delete both. Reboot. The drive DMA capabilities will be redetected.

5. After restarting your computer you will have the DMA mode back on.

Unfortunately my practice says that this can be disabled again. I have not see any issues with Windows XP Service Pack 3. I can suggest you to make sure that your computer is using the latest available version.