I was having problems with Incorrect Valance error message, ran my utilities' repair as advised, (Thanks- seems to be working fine for a bit)- I noticed that my PowerPC G4 shows the OS as 10.3.9. Went to look at the disk that came with my Mac that I carry in my case- It says it's Version 10.4.2. Should I try to install this on my Hard drive? If I do, will it cause me any problems/will I lose anything? Not sure how to do it right, would appreciate directions/advice. I have moved not that long ago, and almost all of my stuff is still boxed up, so no back up drive to mirror my drive to. I can't remember if I had to install the OS on my Mac when I bought it in '05 or not, but the disk that has the OS says it contains a later OS version than what my mac's "About this Mac" states- I'm confused. Would appreciate good advice on how-to, what to do/NOT do- As always, appreciate the help in advance!