. The Clean Install ("Archive and Install") In Mac OS 9 and Windows, the clean install is considered an essential troubleshooting technique. It entails installing a second System Folder or Windows folder | . The Clean Install Archive and Install In Mac OS 9 and Windows the clean install is considered an essential troubleshooting technique. It entails installing a second System Folder or Windows folder a fresh one uncontaminated by the detritus left behind by you and your software programs. In general though you and your software can t invade the Mac OS X System folder. The kind of gradual corruption that could occur in those older operating systems is theoretically impossible in Mac OS X and therefore the need to perform a clean install is almost completely eliminated. That s the theory anyway. In fact somehow or other things do go wrong with your Mac OS X installation. Maybe you or somebody else has been fiddling around in Terminal and wound up deleting or changing some important underlying files. Certain shareware programs can perform deep-seated changes like this too. The point is that eventually you may wish you could just start over with a new perfect copy of Mac OS X. And thanks to the clean install Archive and Install option you can without having to erase the hard drive first. Start by following steps 1 through 3 in The Basic Installation section. On the Select Destination screen though click Options. Now you re offered four kinds of installation. Turn on Archive and Install. Preserve Users and Network Settings should be on too. This powerful option leaves all of your accounts Home folders documents pictures movies Favorites email and so on untouched. As the option s name implies it also leaves your network and Internet settings alone. But it deactivates your old System folder you ll find it later in a new folder called Previous System Folders and puts a new one in its place. And that s exactly what you want. Click OK and then continue with step 4 Section . When it s all over you ll be confident that your Mac OS X installation is clean fresh and ready for action. TROUBLESHOOTING MOMENT Journaling If you decide to erase your hard drive before .