how to reboot my 21'5 imac without installation Cd
iMac, OS X Yosemite (10.10.3)
Can you elaborate on what you are trying to do? You don't need a CD to reboot (restart) the Mac. Are you wanting to re-install the OS, rather than just do a simple reboot?
I had a black screen on my Parallels side and tried to reboot windows from CD, prompt was if i wanted to reboot from mac or windows and chose wimdows thinking parallels but it was for mac side, now i am getting "no bootable device" what should i do?
Maybe you can boot up into the Startup Manager and select the Macintosh HD and hopefully it'll boot.
Restart holding down the Alt (option) key and hopefully you will see your startup disk options. Select Macintosh HD (you may need to use the arrow keys to navigate to it), hit the enter key and hopefully it'll boot.
still only getting the no bootable device message...
Have you tried the Recovery HD and running Disk Utility to see if any repairs are needed to the HD? Restart holding down Command + r. Once booted select Disk Utility - does it see your HD? If so, select it and click on the Repair Disk button. If anything gets fixed click run 'repair disk' again until you get a clear pass and then try rebooting. More info here: OS X: About OS X Recovery - Apple Support
Do you have full backup of your system/files from before the problem arose? You may need it.
how to reboot my 21.5 inch mac without installation CD?
