[QuiGonZel]

A teacher just came to me asking to see if he can take off OS X on his iMac. It runs them both, but he says "It's slow and I think they are conflicting with one another". The mac is a couple years old and freezes up a lot, he says.

The "my iMac freezes up" issue seems to be a frequent complaint. These teachers run a lot of student(special needs) software on them and I guess the question I am asking is:

How do I uninstall OS X off of that mac and just run OS 9? Is this the right thing to do?

[VegasACF]

Without more information it's impossible to fully answer your question. Some iMacs are capable of running Mac OS 9 and Mac OS X natively, some will run OS 9 in only in Classic (that is, must be booted into OS X), and some will only run Mac OS X (an Intel-based iMac) with no option for running OS 9 in any form. I'm guessing you're talking about something from the first two options, but that is only a guess.

It seems highly unlikely that OS X is interfering with OS 9 in any way, or vice versa (be warned, though, not all OS 9 applications are Classic-friendly--in my experience this won't interfere with the boot OS, though, it just won't run in Classic). If one is booted into OS 9 the OS X installation just sits there, idle, just like any other unused application or file. And if one is booted into OS X the OS 9 installation just sits there, idle, until Classic (the Mac OS 9 environment from within OS X) is started.

I think it more likely that the computer(s) are bogged down with extraneous stuff that probably doesn't need to be on the drive in the first place, and that is slowing down the system and/or causing conflicts within whatever OS is the boot OS.

[QuiGonZel]

So the best option would be to go through with a fine-tooth comb and take out the stuff that's eating up all the memory?

[martybowie]

I had an older iMac at home and had problems when both 9 and X were installed onto it. After a clean install of X (without Classic) it completely changed the way the machine ran--it was MUCH FASTER. I would suggest installing just OS X, unless of course all those applications are only available in Classic.

[QuiGonZel]

Originally Posted by martybowie

I had an older iMac at home and had problems when both 9 and X were installed onto it. After a clean install of X (without Classic) it completely changed the way the machine ran--it was MUCH FASTER. I would suggest installing just OS X, unless of course all those applications are only available in Classic.

How do I go about installing just OS X? What's the best way to uninstall a Mac OS?

[martybowie]

Make sure you have all the data backed up from the machine first. Then double check to make sure everything has been backed up. Unplug everything but the mouse, keyboard, and ethernet cable. Put in the OS X CD and boot from it (restart the Mac and hold down the 'C' key until it boots, about 20-30 seconds should do). Then just go through the format process. Make sure you use Mac OS Extended (Journaled) as the format option and you should be OK. Make sure you're installing Tiger from an original OS X Disc. The Mac is really easy when it comes to doing stuff like this. You don't have to worry about drivers/hardware and other crap like that--it just does everything for you! You'll have to reconfigure some settings just as you would if the machine were brand new. Start to finish with the reformat should only take about an hour. Just make sure that you have native applications (and don't need Classic anymore).

[VegasACF]

Before even contemplating such a thing you'd better make sure that you don't have any mission critical applications that won't run in OS X.

Again, I've never heard of such a thing, and have over 20 years experience on Macs. I've run computers of all sorts, with all sorts of OS installations and combinations, and have never heard of a dormant (not the booted) OS interfering in any way with the active (booted) OS.

[martybowie]

I also agree that a dormant Mac system folder cannot interfere with a booted one, that is almost impossible. But, with the older iMacs, having both on the HD does slow it down a bit. I'm not sure if it's the size of HD, the RAM or whatever, it's no doubt slower. I also have 20+ years on the Mac, and I wouldn't have believed it had I not seen it for myself. I think that installing a clean copy of OS X will solve any speed issues. Plus, if its an older machine, its probably never been done before. In fact, when whoever put OS X onto that machine, I'm sure they put it right over the OS 9 that was already installed. That in itself causes various problems which I have encountered on various iMacs (especially the DV line, and those particular iMac models.

[QuiGonZel]

So the general consensus is to do a clean install of OS X?

[martybowie]

As long as you DO NOT NEED to run any older applications within OS 9.

[VegasACF]

I'll say it again, just so the emphasis is not unheeded:

As long as you DO NOT NEED to run any older applications within OS 9.

Be absolutely certain this is the case, or you'll have a far less useful computer after the clean install than before, even if it was choking on unnecessary System Extensions, etc.