Originally Posted by DCJ001
A "clean install" erases one's boot drive and installs the OS from scratch, instead of upgrading on top of the previous OS.
What it does is it gives a "want-to-be-know-it-all" a term with which he can try
to sound like he knows more than the next person. Some "want-to-be-know-it-alls" will answer a question about a problem with an OS upgrade problem by giving the excuse, "well, if you didn't do a clean install, you were just asking for trouble."
I second-guess myself looking for better ways to do things, quite often. But I'm still not convinced that a clean install is better than an upgrade and I won't participate in a debate about it.
I would like to also add that part of the reason is "Oldie Tech Knowledge". When you do a "clean install", you're placing the entire system contiguously at the fastest end of the disc, meaning the inside ring.
I (***most of the time) always do clean installs from disc, repair permissions, then make sure all components are updated (10.6.1 for ex)... and then install my next most resource intensive software, such as CS4. Again, because it will run smoother and slightly faster from the "inside" disc area.
Once all of my main apps are ported.... I again do a permission repair, and then with SuperDuper or CCCloner... make an external disc clone/backup.
I will admit that some of this old tech comes from fooling around with Windows far too long, before switching back to Mac a few years ago once they went Intel. NOTE: also because of bad experiences with PCs, I religiously keep all of my data (other than Mail) separate from my system disk i.e. on a different partition or disk.
*** I actually did a simple upgrade with SL when it came out, but on a clone of my main disk... on both a MacPro and my first Mac (in years), a 2006 2.13 MBP. Both went perfect... and no complaints. However, I still did clean installs on both simultaneously last weekend while watching Vikes lose to the Steelers... the only bad experience the whole weekend.