Just thought I would post my latest experiance. I used to have the following config:

IBM Deskstar 40GB Primary Master UDMA 5
Fuji 6GB Primary Slave UDMA 4
Creative CD-RW 12x10x32x Secondary Master PIO
Relysis DVD 16x Secondary Slave UDMA 4

I went out and brought a Liteon 40x12x48x added it to this config

IBM Deskstar 40GB Primary Master UDMA 5
Fuji 6GB Primary Slave UDMA 4
Liteon 40x12x48x Secondary Master UDMA 2
Relysis DVD 16x Secondary Slave UDMA 4

Win xp would boot and lock my HDD into PIO mode, no matter what config I used both drivers and aranging hardware on different cables the HDD would stay in PIO mode even after a format.

I then tried installing winxp only using my IBM HDD and my CD-RW. HDD was in UDMA 5 and CD-RW was in UDMA 2. Next add DVD that in UDMA 4, now add fuji drive, BANG both HDD back into PIO mode. I then tried it again but added the HDD first that went in as UDMA 4 added DVD and back to PIO.

I have a VIA IDE controller on my mobo and it seems it cant handle more than 4 UDMA devices without win xp thinking UDMA is having a problem and locking the drives in PIO mode.



This works on Win Xp
look for this key

“DriverDesc”=“Secondary IDE Channel”

This is for the secondary IDE channel on VIA systems. I had a problem where a Creative 52Xmx was recognized as PIO. It was set at secondary slave.

The main keys here are:

Again for IDE2. Make sure where is it located and DELETE the apopiate key then reboot. The system will recognize it again. That’s how I fixed my problem and it works like a charm.

If it is for IDE1 look for this key (search in regedit):


Its not a problem with the devices being recognised properly. Win XP detects a “problem” on my primary IDE channel as it seems the IDE controller cant function properly with 4 UDMA devices. When it detects this it goes and locks my HDD in PIO mode as it thinks there is a UDMA problem. Only solution I found is to only have 3 UDMA devices on my mobos IDE controller. If I reg hack it will change them but they do not run it that mode (benchmarked them before a reboot) and win xp will not reboot


The registry hack does work…I did it myself.

However, what you are mentioning looks more like a hardware problem. Does this happen with XP’s default controller drivers and latest VIA’s?
If the answer is yes and you are on a budget I recommend you to get a ATA 100 controller.

Hope this helps.