It should bring up up enough to run Disk Utility but I suspect you corrupted the OS somehow at the shutdown.
If you are unhappy with the performance of a program, try a Force Quit which will just shut down the offending program and leave the system alone.
It may take a while to boot with the Shift Key down and will take quite a while to reboot normally. There is a lot going on during the boot process
Good luck
P
after beibg frustrated with my iBook trying to load internet pages, I shut down improperly by holding down the power button. and when I attempted to turn the computer back on, it gets stuck at the loading page, continually truing to load mac OS X but never gets anywhere. any advice?

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