Software update of OS won't work...

I have a PowerBook G4 running OS 10.5.1. When I run software update, it pulls 10.5.7. When I run the installation, the system hangs on the "installing 1 item" screen (the blue bar stops about 1/8 of the way across). Any ideas on how to complete the upgrade? Thanks to all.

im not a mac expert by any means but you could try downloading the combo update from apples site, i think its aaple.com/downloads. you can then install the update via a dmg file.

failing that theres a few steps below that recently helped me. I am on 10.6.4 so there might be slight differences that i am not aware of.

try moving the software update preference files to the desktop and run software update to see if that resolves the problem (move to trash if it does).

they are located:

/*user*/library/preferences/com.apple.SoftwareUpdate.plist

and also in root of the HDD:

/library/preferences/com.apple.SoftwareUpdate.plist

if that fails then you could run software update from terminal and see if works there.

sudo softwareupdate -i -a

also you could try creating a new user and run software update to see if the problem is only with the one account

Let us know how you get on

Is the best way direct from 

10.5.7 Combo Update

or

10.5.8 Combo Update