In the event of a major glitch, you may be forced to relocate to new Mac OS X on your partition / hard drive. Sometimes the only solution left when giving out any is to reinstall! (rare, but no one is safe from a big system problem ... often caused by a clumsy user besides).
But before proceeding with a restoration / re-installation, I recommend installing the last Updated COMBO of your system (PANTHER, TIGER, LEOPARD, SNOW LEOPARD). Directly on your OS X volume Installation / relocation of last Updated COMBO sometimes allows miracles!
Note: A combo update is an update incorporating all previous updates of the system. For example, the 10.4.11 Combo Update includes all the updates since 10.4.0.
Why it is necessary to make a new installation of Mac OS X?
- The best solution is to first create a clone of your OS X volume on a partition on your external hard drive. If this is not yet done so, I would strongly advise you to buy an external hard drive (firewire or USB 2 but bootable to OS X) and aslo invest in some cloning software so that you can create a clone. It is without doubt the best safety precautions you can have.
If you have a clone, then start booting onto this clone (by selecting it as startup volume in the dashboard "Start" in "System Preferences"). Suffice it then start your cloning software from this clone to delete and then clone back to your main volume. Then select your new volume of "OS X" in the main scoreboard that is given by "Start"! That's it! Everything is as before!
- If you unfortunately do not have a clone / backup, then the only solution is to bring your installation DVD of Mac OS X, then completely initialize your partition / volume OS X (after having backed up your data) and reinstall OS X from the installation DVD, then run "Software Update" (menu "Apple") to get your system updated.
Then reinstall your applications, files and personal documents etc.
Tip: Note, as and when they become available, update your software to stay up to date with the latest versions thereof. It is well advised to download (on macupdate.com example) these different updates to have them always under your needs.
That said, I never needed to reinstall the system since the beginning of Mac OS X, demonstrating its incredible stability, and therefore this type of operation should not be frequent.
Also make regular backups of your applications and documents (On DVD-RW or FTP server for example, or even using the cloning technique), so if you were to fail for one reason or another, you can always retrieve your backup and thus avoid a re-installation.