Is it best to do a clean install when upgrading to 10.5? I know its a hassle to reinstall everything and I hate doing that especially since I have so many songs on I tunes, and I will have to reinstall my graphics card software, but is it best to do a clean install? When I updated to 10.4.11 and rebooted it got stock on that loading screen for an hour until I hate to reboot the machine since I heard the HD stop reading. So I rebooted and everything was fine after that. I just figure if I do a clean install any errors on the HD should be fixed since I will be starting over.

I don't think I've ever done a clean install, at least not since 10.1 (I did do it from the PB to the first "real" release. I know a lot of people swear that they have much better performance with a clean install, but I'm just too lazy.

I know a lot of people who swear that:
an oil change makes their vehicle immediately drive smoother,
a big dose of vitamin C wards off a cold,
using premium gas makes their car run better.

All of these, including the clean install, are examples of the placebo effect. You do something that you think should make you or something run better. You pay money or time for this something. And of course it does make you feel better even though there is no data to support the improvement.

Placebo. P.T. Barnum did not die a poor man underestimating the human condition.

So is it normal the first few times rebooting after an upgrade it takes the computer a little longer to load?

Loading times vary so much from reboot to reboot that almost anything is normal!

Yes, MacOs X after an upgrade can actually take hours if not days to stop whirling in the background. Depending on the devices attached and the size of drives this can take a while. It may have to look at every single file make a copy, look at it, compare it to the old copy, turn it over, kick the tires and delete the old file. If you computer has been running for ages this could take a big chunk of time.

Far easier than erasing and rebuilding from scratch. That dinosaur idea is left over when everyone wanted to put the ones and zeroes making up the boot up system near the center of the hard drive in one continuous stripe. That is meaningless now.

I did the same with my MDD, always just upgraded since 10.2. I was having lock ups for quite a while, daily, and figured a clean install might help. Unfortunately it didn't and my record of 5.5 years on an installation was now gone.

I did finally fix it of course. It turned out to something with the front ATA bus. I removed those two drives, and the cable, and it has been rock solid for over 2 months now, just haven't had the time to see if it was the cable, bus, lack of power, (I also have a different video card) or one of the drives. I was just happy to not have to buy a new machine, this one serves me fine.

I do clean installs when I don't know what third party crap someone might have installed, and I want to start with a clean system so that when I trouble shoot I know the scoop. I've done enough installs to know it's not just a placebo effect sometimes, it all depends on the situation.

Reinstalling does clear caches, font caches too, which is one reason the reboot after an install takes so long, it seems to hang just before the desktop loads to reload font caches, during startup has to rebuild other caches.

Ok thanks, I left it for an two hours one time on that blue screen with the beach ball but the HD was all quiet, so I just power cycled and then it worked. Maybe that is a bad idea?

Nope, a laptop I was working on over the weekend did that after I shut it down after Target Disk mode use, then rebooted. It hung at the blue screen for some reason.

As long as the HD was quite it's usually safe to kill the power since it's not writing to the drive.