DVD drive stuck in PIO (on XP)?

[Jukka]

Is your DVD drive stuck in PIO mode?

Follow the instructions below for the fix:

Open RegEdit
Find the following KEY

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Contro l\Class\{4D36E96A-E325-11CE-BFC1-08002BE10318}\000x
The last four digits will be 0000, 0001, 0002, 0003, and so on.
Under each key, delete all occurences of the following values:
MasterIdDataChecksum
SlaveIdDataChecksum.
Reboot the computer. Windows will now redetect DMA settings.


I found this at http://www.tongfamily.com/000392.html

Jukka

REMEMBER: Arsing around with the registry can be dangerous. Do it at your own risk.

[johns0]

Its easier and safer to uninstall the afflicted ide channel in control panel/system/hardware/device manager and reboot.

[Jukka]

Thats what I thought, but that doesn't always fix the problem.

My main question though is how does it ever slip into PIO mode (mine was set as UltraDMA for ages)?

[Wolfmancatsup]

I believe XP drops the rate at which it "talks" with the drive each time it sees an error, so if you start at DMA 2, and it gets errors, it'll eventually drop down to PIO mode.
I've noticed this happen a couple of times with my old cd rewriter when I had a fair bit of stuff running at the same time as reading a cd. I only had to open a new window up, and that brief hiccup seemed enough to cause WinXP to drop the mode.
When this happened, I just deleted the IDE port the drive was on and then searched for new hardware to restore it at the correct DMA.

Wc