Dunno which OS you're using, but - assuming it's a Windows derivative!

- it can't be much different to the W98 that I use.
The good news is that you don't need any additional software to change the DMA setting of your drive.
Simply go to 'Control Panel' and select 'System'. Now go to 'Device Manager', making sure that 'view devices by type' is selected.
You should now see your system's components listed. Click on 'Disk drives' and your hard drive(s) will now be listed - as 'GENERIC IDE DISK TYPE 47', on my system. Right-click each of these listed drives and a option window will pop up. Select 'Properties' on this window and a window specific to the drive will appear. There are now three tabs: 'General', 'Settings' and 'Driver'. Click on 'Settings' and you'll see a list of options with tick-boxes alongside. If it isn't selected, click 'DMA' so that the tick appears and then click the 'OK' button.
You'll now be told that a restart is required and asked if you want to do so now. Select 'Yes', wait for the reboot and DMA should now be applied.
It's late (or early

), but I think that's all. Good luck.