Resolved iMac boot error: "No bootable device -- insert boot disk and press any key"

[Maxwell Lopez]

My iMac keeps trying to boot in to windows but doesn't seem to find the partition. I tried holding every key combo and nothing is working. Hard drive spins up and everything, I'm unsure how to fix this issue.

 

[Maxwell Lopez]

My iMac keeps trying to boot in to windows but doesn't seem to find the partition. I tried holding every key combo and nothing is working. Hard drive spins up and everything, I'm unsure how to fix this issue.

This happened while I was switching from mac os to windows.

 

[HDFan]

I tried holding every key combo and nothing is working.

Which specific ones did you try and what were the results?

 

[Maxwell Lopez]

Which specific ones did you try and what were the results?

shift, option, cmd r, cmd s, cmd option p-r. Cmd v. All of them didn't do anything, just takes me back to the boot error. Another thing I didn't mention is that i booted into mac os on a externtal harddrive, I tried booting into windows from there. Don't know if that caused issue.