DMA disappears, only PIO left WTF?

Got a C, D, E, and F letters for drives. D is a dvd-rom burner, C, E, F are HDs. C and E were primary master and slave, D and F secondary master and slave. Got a new HD today. Wanted to switch it in to back stuff up. First took out the E and replaced it with the new drive. Worked fine. Then turned off the power, unplugged it, replaced the primary slave with the old E, and set the new HD as secondary slave where F was. Started up, first strange thing old E is now set as F, new drive is still E despite the change in position. Started transfering things when I noticed the slowness and the massive CPU usage. Must've switch to PIO. Checked and it did, but no options to change it back. I uninstalled the secondary IDE channel (it was the one affected). Restarted, still PIO. What now?

What motherboard do you have?

In the meantime, check BIOS settings.

That's strange, usually unistalling the device should reset back to DMA automatically, unless there's still something glitched up in your setup.

If using nvidia crap, then DO NOT install nvidia IDE drivers, as they are real crap.

Check that your IDE cable is ok. Ok means no sharp angles or anomalies. And 80 wires, of course.