My iBook is taking ages to update

Hello,

I have recently been given an iBook G4 and when opening iTunes it came up with a message telling me to search for recent updates, i pressed search and it came up with 2 updates one was for iTunes the other was for a more recent update for the iBook, i've have started the update but its been on the same bit for about half an hour, there is a pop up in the middle of my screen with a loading bar and above says 'Installing 2 items' and underneath it ' configuring installation, like i said the bar hasnt moved in the past half hour, can someone let me know if its crashed or have i just got to wait it out?