My Mac has got 2 System Folders on it
That's impossible. Two folders cannot have the same name. Hence, you do not have 2 System Folders. You may have a folder with a different name but similar, but computers will not be confused.
Anyway, this isn't the reason your computer will not boot.
Try holding down the option key then power on. This brings up the startup manager. Click on your hd. Click on right arrow key. See if you can get this to work.
Shutdown your machine. Hold down the shift key. Poweron. Wait awhile Wait awhile while you harddrive
is being checked.
I suspect disk corruptions.
verify & repair your startup drive
To verify & repair you file system on the startup drive, you will need to run disk utility from you installation DVD.
This article will tell you how to get to disk utility. Once in a disk utility, you can go and attempt to recover the disk.
To repair your startup drive, you will need to run disk utility from your startup DVD.
Mac OS X 10.4: About the utilities available on the Mac OS X 10.4 Install DVD
How to run disk utility from your startup DVD.
- Insert your startup DVD into your reader. Power down your machine. Hold down to the c key. Power on your machine. This will bootup your startup DVD.
- This will bring you to a panel asking you for your language. Pick your language.
- You you come to the Install Mac OS panel. Do not install.
- Click on Utilities menu item. This will give you a pulldown list of utilities.
- Click on the disk utility.
- You are now in disk utility. Pick your disk. Click on repair it should be on the lower right of the panel.
- Once the repair completes successfully, you should update your permissions.