when i start my imac it shows"no bootable device-- insert boot disk and pess any key.what shoul i do, when i start my imac it shows"no bootable device-- insert boot disk and press any key.what shoul i do

Do you have Windows on this machine?

You didn't try to put Windows on? because that is a Windows message.

Then I have no explanation for why that message is appearing, look over to the right on this page, others with the same issue have posted, read them.

Boot to the installer disk, don't install, instead go to the Utilities menu, choose disk utility and repair your drive, if it does not show post back.

Do you have backup of your data?

Do me a favor and try this after you repair the disk:

Restart and hold down the option key at the sound of the chime until you see one or more disk icons. Select the one representing your Mac OS boot volume and press return. When the boot is complete, open System Preferences > Startup Disk and set the Mac OS volume as the default boot device.

Note what (if any) other drives are present.

You're welcome, and thanks.

Were any other drives listed in the Boot Manager?

Thank you Csound. I just installed a new security update and got that message. I followed your instructions and its working! Because of you I am having a great day! Thank You!!

oh I had 2 other drives come up - the restore drove and the seagate backup for my time machine. when I went into system preferences, only the Mac HD shows. In fact, since there were no other choices it would not let me change the preference; but i rebooted anyway just to make sure it would work and it did.

Thanks again!

jdenvers wrote:

Thank you Csound. I just installed a new security update and got that message. I followed your instructions and its working! Because of you I am having a great day! Thank You!!

You're welcome