Help! Another dreaded blue screen, cannot fix

[bandwidow]

My husband updated 10.4.11 to whatever was listed yesterday in Software Update, and now he has the dreaded blue screen (apparently 1 of many!).

G4-450. 2 internal hard drives, one running 9.2, one running 10.4.11
* Ran Diskwarrior twice.
* Can not safe boot
* Original OSX CD boots up to a freeze
* Zapped the pram
* CAN boot up to hard drive running 9.2 and select files on both hard drives (but cannot open link to G4 from G5)
I could really use some suggestions for the next step (step-by-step).
Also, if I boot up to the 9.2 drive, what files should I access to try to remove the update, if that would help?

Please, please help me.