It's been roughly 72 hours since Mac OS X 10.5 Leopard was released. Many (if not most) users are reporting no problems installing or using Leopard. Unfortunately, a significant number of others are having problems, many of which are severe. If you haven't installed Leopard yet, or if you have installed Leopard and are experiencing "issues," I encourage you to read this column from start to finish and visit all of the page links it includes.

I don't want to be an alarmist but a good number of users are experiencing the extremely nasty Blue Screen of Death (BSOD) after installing Leopard. When the installation completes and they restart (or their Mac restarts itself), a plain blue screen appears and nothing more. Keystrokes have no effect on it and a hard (power button) restart just brings the blue screen back again and again and again.

I know... because it happened to me. I got my copy of Mac OS X 10.5 on Friday around noon. Since I had already backed up and cloned my boot disk in anticipation, I ripped open the package, slammed in the DVD, and started the installation.

Before I detail what happened next, allow me to digress for a moment. Last Tuesday in my Dr. Mac column for the Houston Chronicle I offered my three simple rules for upgrading Mac OS X:

• Don't be the first one on your block
• Wait for the first bug fix release if you can
  and
• Back up important data

It wouldn't hurt you to read the entire column (click here), but either way my point was:

Remember that the pioneers take the arrows and let the trained professionals, such as yours truly, take them for you.. let us discover the inevitable incompatibilities and issues and report them before you upgrade... read anything and everything you can find about Leopard before you install it.

So, where some Mac writers may have installed Leopard on a separate Mac, hard disk, or partition, or selected the Erase and Install or Archive and Install option to insure a cleaner, fresher installation of Leopard, I chose to perform the default Upgrade installation on the startup disk of my main everyday writing Mac (a MacBook Pro). You see, I firmly believe that if I'm going to write about this stuff I have to "eat my own dog food," to insure that if something went awry with my installation I would experience the same degree of terror other users would experience.

Which was just what happened. My Leopard installation went fine right up until the very end when I restarted my Mac. After that, the blue screen of death appeared and no amount of clicking, keystroking, or restarting would make it go away. I was blued, tattooed, and totally screwed. If I were an average user, I'd be having a massive stroke right about now. But being your intrepid reporter, I calmly walked into the den and fired up Safari on my kids' Mac. But because it was still a few hours before the official 6PM Leopard launch, the Web was completely bereft of information that might have helped me. As far as I knew I was the only one on earth experiencing this BSOD thing.

I wasn't ready to throw in the towel and perform an Erase and Install or Archive and Install just yet, so I did what I would have done if Tiger had blown up -- I booted into UNIX single user mode (by holding down Command+S at startup) and ran the file system check by typing fsck -fy at the prompt. It reported an invalid volume free block count and repaired it. Since the file system had been modified, I ran fsck -fy again and this time received a clean bill of health. I then typed reboot at the prompt and my Mac restarted.

I held my breath. Would the BSOD rear its ugly head? For about 5 minutes I was afraid so, but then the Leopard login window magically appeared. I logged in, but while everything looked OK my Mac was as slow as molasses in January. Next, some error messages informed me that I had several font conflicts. So I hunted down the suspect fonts, disabled them, and restarted.

After logging in again, things were still sluggish and I experienced nearly a dozen error messages and a kernel panic over the next few minutes:

The next thing I tried was to launch Console.app and look at some log files, hoping to find a clue about what was gunking up the works. I didn't, but since System Preferences had quit unexpectedly three or four times, I got to thinking perhaps I had incompatible third-party System Preference panes. So I moved roughly half of my third-party System Preference panes out of ~/Library/Preference Panes and /Library/Preference Panes.

I thought another possibility was a renegade Login Item so I also deleted every one of the Login Items from my Accounts System Preference pane.

I rebooted and held my breath again and...

Success! After several hours of terror and frustration and more than a dozen reboots, everything was working properly. Furthermore, I have had almost no trouble with Leopard since then. Time Machine is doing its thing beautifully. Spaces is a little rough around the edges but still more useful than I ever thought it would be. QuickLook and Cover Flow in the Finder are a treat. And Mail is working perfectly and seems a bit faster to boot.

Once I was certain my Mac was stable (or relatively stable), I spent a good part of the next two days reading everything I could find on the Web about Leopard installs so I could write a (hopefully) helpful column about it. The bad news is, I wasn't the only one to experience the BSOD -- not by a long shot. The good news is that it doesn't have to happen to you.

First, it appears that using either Archive and Install or Erase and Install instead of the Upgrade option avoids the BSOD. Almost all of the reports of BSOD I've seen were from users who used the default Upgrade installation. On the other hand, there are plenty of users who performed Upgrade installations successfully, so take it with however many grains of salt you wish.

That said, before you install Leopard it would behoove you to read some or all of both the official and anecdotal information about Leopard installs available on the Web. There are already thousands of pages with more being added by the minute. Some of the more useful ones I've found are:

• The official word on the BSOD from the mothership (Apple Article ID 306857):
  Mac OS X 10.5: "Blue screen" appears after installing Leopard and restarting
  
• Main Apple Discussions category page:
  Category : Mac OS X v10.5 Leopard
  
  
• A massive Apple Discussions thread about the BSOD:
  Topic : Installation appears stuck on a plain blue screen
  
• Another massive Apple Discussions thread about the BSOD:
  Topic : BLUE SCREEN freeze, fixing after Leopard install
  
• An Apple Discussions thread about the Finder not working after an Upgrade install of Leopard:
  Topic: No Finder!

• Apple's official Leopard support pages:
  Support: Mac OS X Leopard Featured Topic
  
• Apple's official .Mac + Leopard support page:
  Support: .Mac and Leopard
  
• MacInTouch Reader Report:
  Leopard

Although I had some trying times on the way, after only a couple of stable days I'm beginning to like Leopard a lot. If you will just take a little time to prepare for and plan your upgrade, you can probably avoid the trying times and get straight to the liking Leopard part. Goodbye and good luck!

And that’s all he wrote…