How to force Ultra DMA for your Hard Drive or optical drive instead of PIO (Working solutions)

Hello guys, today on our 'How to' we're going to learn how to force your HDD or optical drive device to use Ultra DMA instead of PIO or multi-mode mode, these last two mode are too slow and use lot of CPU resources, but the Ultra DMA mode use the RAM as a buffer memory instead of direct access to the CPU, this help to boost read/write speed.

For me the PIO or multi-mode mode make me drives run very slow and with errors, and I cant switch to DMA mode specially when I switching between HDDs without shutting down my PC.

To force the DMA mode, you just need to access these Windows registry address by going to Start->Run and type "regedit" then go to this address:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4D36E96A-E325-11CE-BFC1-08002BE10318}

You will find something like sub-folder or subkeys like 0000, 0001, 0002, etc, the 0001 is the primary IDE channel, 0002 the secondary and so on, search for your affected IDE channel on the Windows device manager and delete the whole sub-folder, then restart your computer and your done, the DMA must be set. 

(thanks to the tuts over winhlp.com)

Alternative solution if the up one doesn't work:

• Try to uninstall the divice from Windows device manager and restart your computer.

• change your HDD/optical drive ports to another one.

If you still have please problems let me know on the comments.