NTLDR error with multi-boot setup

I have installed WinXP on separate hard drives. I am manually plugging in only one of the 2 drives at a time so there is only one physical boot drive (C installed. (I should note that each drive has its own SATA connection to the mobo, since I plan on using DD to hide one of the drives and select a boot drive from the mobo boot sequence, thus avoiding having to physically plug/unplug drives.)

I also have another drive (D in the system for data. I am getting the NTLDR boot error when I connect either one of the two boot drives with D: connected. However, if I disconnect the D: drive, either C: boots just fine. Then if I power down and reconnect D: after C: has successfully booted by itself, all is well. But when I switch to the other boot C: drive, same problem happens and I have to go through the steps to make it all work. (If I select the boot drive manually during the motherboard boot sequence, I can get things to work...but I have to do this on every boot.)

When both C: & D: are connected and I boot from the DD CD, it is showing my data drive as C: and C: as D:, which is wrong and probably the source of the NTLDR boot error problem.

D: is not a boot drive, no OS installed. But it is partitioned as Primary, Active. Could this be the reason why I am getting this drive letter confusion? Could the fix be to remove the partition and reformat as Logical?

 

pestoking,

Do you have the OS HD plugged into SATA Port 0? And the data HD into SATA Port 1,2 or 3?

 

It's possible the booting drive (or boot order) in the BIOS is being changed every time you change drives. That happens on one of my computers (it has a mixture of IDE and SATA, though).

 

On the mobo, the one OS boot drive (#1) was plugged into SATA 0. SATA 2 is for the other OS boot drive (#2) (not connected).

When all are connected, according to BIOS, Boot Drive #1 is "Channel 0 Master" and Boot Drive #2 is "Channel 0 Slave" (remember, only one drive was connected at a time). Data Drive is "Channel 1 Master". I also have another Data Drive, which is showing up as "Channel 1 Slave"

I have more details, see my reply to MudCrab.

 

That's exactly what's happening. Even though I have only one boot drive physically connected, if any of the data drives are also connected the boot order is messed up UNLESS I force the issue during the system startup and select a drive to boot from, then there's no drive letter confusion.

I have moved forward connecting all drives (2 with WinXP and 2 data drives). I then boot to the DD CD and hide one of the two OS boot drives. Then, I reboot into BIOS and tell the system to boot from the non-hidden drive. To use the other boot drive, I do the same routine again (hiding/unhiding using DD & tweaking BIOS boot order). All works just fine this way, no hiccups. It's a two-step process to switch between my two XP boot disks, but since I don't switch every 5 minutes I can live with this.