Windows 7: Computer Will Not Boot Automatically When Second Drive is Added

I recently replaced my boot drive and just got everythign up and running. I had removed my backup drive while I replaced the boot drive so that I could us it on another computer.

Now when I add the 2nd hard drive back to my computer I get a message saying something like "can not load os" right after the bios screen comes up and before Windows begins to load.


If I unplug the second drive the computer will boot just fine.


If I access the boot menu and select my boot drive the computer will boot and my second drive will work just fine.




Any ideas how to fix this so that I do not have to enter the boot menu and select the boot drive on every startup?

When plugged in your secondary HD is assuming first HD to boot so it needs to be set to boot second after the primary OS HD.

In some cases conflicting boot code on another HD can interfere so if the secondary will not be set as second HD to boot, or interferes when it is set that way, move the data off and wipe it with Clean command: Disk - Clean and Clean All with Diskpart Command.