Ask Max: Do I need to keep a folder called "System Folder 9" on my OS X system?
I have a G4 Mac and am using OS 10.4. I have on my hard drive a folder called "System Folder 9". Do I still need to keep this on my hard drive even though I'm using OSX? Can I just delete the folder?
The question of whether you need an OS 9 System folder on your OS X computer depends on what software you use. The OS 9 System Folder is installed on some OS X Macs so that the "Classic" environment will work. Classic will allow Power PC-based Macs to use OS 9 applications in OS X. This is particularly helpful for longtime Mac users who have old programs that were never rewritten for OS X. I still use one or two and so keep Classic on my computer just for them. If you do not have any old applications, then you can safely remove the "Applications (Mac OS 9)" and "System Folder" from your computer.
An OS 9 System Folder is not always easy to remove because the OS X operating system actively references it as part of Classic. The easy way of removing it is to go into the System Folder and moving the file "Finder" to the trash. Then you need to restart the computer. After the computer has restarted you can move the whole System Folder to the trash. Most likely you will have to enter your Admin user name and password to make that move. I would discourage you from emptying the trash for a week or so until you know that you don't need Classic for any of your applications.
Hope that works well for you.