Dual Boot Win 7

I have a Dell Precision M90 with XP on a SATA drive and Windows7 on a separate SATA drive. Either one in the HD port and it boots fine.

I purchased a Caddy for the DVD slot and put the XP SATA drive there and it boots on Win7 and even with the correct boot order in the Bios it will not boot on the XP in the DVD slot. This is with or without the Win7 drive installed.

Is this possible to have it dual boot from different physical hard drives and if so, how is this accomplished?

I have seen in the threads talk about the Boot Menu; is this the Bios menu or a separate program?

Thank you, Bob S.

There are two different boot menus; which one or ones you will see depends. From your description, I guess that each of your drives is individually bootable.

First of all, help me figure this out. The Precision M90 is a notebook computer, yes? So by the HD port you mean wherever (I'm still trying to pull up a manual) the HD is usually installed.

When you boot from Win7, can Win7 see the XP drive at all? If it can, this suggests the simplest solution. If it can't see the XP drive, ignore the rest of this and let me know.

I can't find the manuals to see if it's possible to START the boot process from a secondary drive, but it is certainly possible to POINT the boot process to said secondary drive once it starts off the primary.

Specifically, the boot process starts with BIOS, loads the Master Boot Record from the boot drive (you are trying to change the boot drive), runs a small OS loader, then does the same thing with the Partition Boot Record for the partition containing the OS you wish to run. If your machine won't let you load the MBR from the secondary drive, you can just twiddle the Win7 boot loader to recognize the XP installation and boot from it. If that wasn't clear, ask me to explain further.

What you will do is: First, back up both disks, so that if my advice ruins your system you have a fallback plan. Then download a free utility named EasyBCD and run it. I am no expert on this; it was so easy that all I did was follow the directions on their site. Run EasyBCD as an administrator and have it add the XP installation to your boot menu. Next time you boot, it will
1) Boot using the MBR from the Win7 disk, ignoring the MBR on the XP disk
2) Load the Win7 boot loader
3) Ask you which OS to boot
4) If you select XP (or "previous windows OS" ), it will continue loading from your XP disk and XP will run.

Do you have enough space on the internal drive to clone your XP partition there so that you can run either OS with just one disk and save battery power?

RAS_Cincinnati: Your reply got lost. All I see is a copy of my own post. Note that you can reply without it by either using the tiny, cramped, and unformatted "Quick reply" window, or by hitting Reply to WyomingKnott and then deleting the quoted version of my reply.