Currently Being ModeratedNov 7, 2012 6:16 AM (in response to VedantMathur)
Forgive me I'm confused here.
You say you can't eject the disk or you simply can't boot from the disk? Or both?
It's possible to Boot from your USB drive.
Here is a link that may help you http://ben-collins.blogspot.co.uk/2010/08/booting-your-ibook-g4-from-usb-stick.h tml