How to use advances startup options to troubleshoot issues on most iMacs

[spyjake1]

Here is a few advances startup options you can use to troubleshoot your Mac.
*Only on SOME macs

Here is the list (Note, to use these, hold the buttons listed during startup.)
*Only Some iMacs
** ADVANCED OPTION ONLY (DONT MESS WITH THESE)
Button(s) - - - - - | Effect - - - - -
Command+R Boots into Recovery mode (OSX Lion+)
Shift Boots into Safe Mode
D* Boots into Hardware Diagnostics
Option Opens Startup Manager (Boot device selection)
Command+S** Boots into "Single User Mode" (Terminal/Command Prompt)
Command+V ** Starts up in "Verbose mode" (normal boot+debug messages (dont get scared)