I upgraded the OS on this computer and now it won't boot--just grey screen with spinning gear--no question mark. Will boot from external drive. I have wiped the drive and done a clean install. Runs fine when I have the original OS10.3 installed, but won't upgrade even to later 10.3 updates,
I upgraded the OS on this computer and now it won't boot--just grey screen with spinning gear--no question mark. Will boot from external drive. I have wiped the drive and done a clean install. Runs fine when I have the original OS10.3 installed, but won't upgrade even to later 10.3 updates,