Hi all, I need some help figuring out the dual-drive, dual-boot installation. I've read and reread every post I can find, tried it several times and subsequently recovered several times from botched attempts. I simply cannot get it to work.

I have XP on the primary, and Linux on the secondary. I know about the usual way of installing grub in the MBR of the first drive, but I lost Windows in the process, and ended up having to restore the MBR. Now I'm trying the approach that uses the Win boot loader. Following a procedure I found on the web, I let Linux (in this attempt, Mepis) partition the second drive as it liked, and had it install grub on the root partition of the second drive. Then I used the "bootpart" utility, following instructions, to modify the boot.ini and create a file from the first sector of the second drive, using the LBA option. When the machine boots, I am presented with the choice of XP or Mepis - XP boots fine but choosing the Linux boot gives me:

"Cannot load from hard disk, insert system disk and press any key."

From here, I thought I would try the trick where you switch the bios to boot from the second drive, just to see if it would work. Unfortunately, I can't figure out how to do this. When I go in to the boot setup, my primary IDE drive 1 says "no device". I tried switching it to "auto", but still it's not recognized. Is that normal, or is that telling me that something is wrong with the way the second drive is fomatted?

Your dodgy BIOS setting is probably the source of your problems. Check the jumper settings on both drives and make sure that one is slave and one is master. You will probably find that this is not the case. Cable select is not really advised. If your IDE (I assume you're not using SATA) cable is jumper specific you will also need to take this into account. My advice would be this.
Change your secondary drive and set it as master.
Change the primary drive and set it as slave.
Format and install linux with grub, accepting the default values.
It should then see XP on your (now secondary) drive and after install you should be good to go.
Regards
Chris

Thanks for the suggestion, and I'll give the the disk swap a try. I'm fairly certain the jumpers are ok, as I put the second drive in and have been using it in various machines for a few years as a slave drive, but I'll check when I get in there. If I swap the disks, I have to do the map trick in grub to make Windows think it's on the primary, correct? When you say "format and install linux with grub", what did you have in mind with the "format" part? Should I reformat the drive with just a single primary partition, like Fat32 or something, and then let linux reformat it during the install?

No need to format before you install linux as it will just re-format it anyway. You dont need to make Windows think it is on the primary, just as long as GRUB is installed to the MBR - Master Boot Record - on whichever drive is the master. It will then boot linux of you select that option or hand off to Windows on your secondary if thats the option you choose (obviously by mistake )
Regards
Chris

I finally found a few spare minutes to make the drive switch and... it didn't work. I jumpered the second drive as the master, the first drive as the slave, and then reinstalled Linux on the second drive, installing grub in the MBR.

A nice, graphical grub boot screen comes up, showing Mepis and Windows options. Mepis loads fine, but choosing Windows just brings up a "second" grub screen (all in text), with the same options. Choosing Windows just loops back to this second screen.

I edited menu.lst just in case, and added the map entries, but that didn't have any effect.

I think the best option at this point is to make a home video of this machine getting tossed out of a third story window. After three months of trying and failing to get it to dual boot, I'm convinced it's possessed. This is one of those off-the-shelf Dell Dimension home desktops - if anybody out there has added a second drive to Dell box and managed to get it to dual boot, I'd love to know what you did - in gory, newbie detail. I'm still not convinced that the Dell hidden partition isn't screwing this up some how.

Here's a summary of what I've tried to date:
1. Linux on slave, grub on MBR of master. Wouldn't boot Windows (can't find OS error message); had to fixmbr to recover.
2. Linux on slave, grub on root partition of slave, Windows boot loader chaining to grub. Wouldn't boot Linux; get "insert system disk" message.
3. Linux on master, grub on MBR of master, Windows on slave. Won't boot Windows; no error message, just brings me back to the grub screen. Mapping had no effect.