Question Anyone know how to boot to another hard drive on older Dell PC's?

MajorPager

Prominent
Aug 8, 2023
327
43
710
I have a couple of older Dell PC's that I use that I want to boot to different hard drives that have different OS's. Specifically the Optiplex 745 and XPS 400, I cannot find an option to boot to different drives or even switch the boot priority. What should I do about it?
 
To clarify:

The requirement is that each host computer (an older Dell desktop) has two installed hard drives.

And at boot time you wish to be able to select the hard drive hosting the operating system you wish to use.

Is my understanding correct?

What OS's are you using?
 
The Optiplex 745 has Windows 10 Installed on the primary drive, and has Windows 7 on the secondary drive, and also has Windows XP 32/64 on another secondary drive that isn't installed.

The XPS 400 has Windows XP MCE on the primary drive, and I was hoping to put Windows Vista on the secondary drive.
 
I have a couple of older Dell PC's that I use that I want to boot to different hard drives that have different OS's. Specifically the Optiplex 745 and XPS 400, I cannot find an option to boot to different drives or even switch the boot priority. What should I do about it?
Can you physically switch the drives?
 
The Optiplex 745 has Windows 10 Installed on the primary drive, and has Windows 7 on the secondary drive, and also has Windows XP 32/64 on another secondary drive that isn't installed.

The XPS 400 has Windows XP MCE on the primary drive, and I was hoping to put Windows Vista on the secondary drive.
Just a guess if you have an option called legacy bios play with it see if these other drives then show in the boot order.
 
Somewhat nonintuitively, it's under "Boot Sequence." It looks like there you can only enable/disable things there or move them up and down in the boot order, but you can actually highlight "Hard Disk" and then press Enter to get a popup menu to select the make and model of drive to boot from.

Obviously every drive you wish to boot from must be partitioned MBR with an active partition.