Follow the instructions in the link below to download and run a registry script to fix the DMA settings.Occasionally, settings will appear as if they've enabled DMA but upon a restart, they got back to being PIO.. Use the script to make sure.
Hope this helps.
I am using a dell dimension 2400 desktop with windows xp professional. I am trying to burn a dvd-r, from different programs such as poweriso, roxio creator, and nero 8. it used to take approximately 25 minutes to copy a full dvd-r, and now it will take an hour or more. I have optimized my registry, with registry mechanic. I have ran a virus scan with eset nod 32. I have reset the DMA, and I have ran a scan with stopzilla, and nothing seems to make the drive speed up to where it used to be. It is a brand new lg IDE dvd dual layer rw drive. Can anybody help? I can't figure how to restore the speed it used to get!