If you have an early model MacBook Pro, the odds are high that you need to go to the Apple Genius Bar to get Snow Leopard installed. I hope this message saves you some time and frustration if you own an early MacBook Pro.

The story behind my advice: I read Terry White's reports of installing Snow Leopard in about one hour for each of his computers. Relieved at the prospect of an easy-install, we bought the Snow Leopard Family Pack.

I inserted the DVD and got the expected grinding and growling. Then a repeat, which signaled trouble. Soon the disk ejected. I repeated that cycle several times. It would not open.

I inserted three different CDs, which opened. Then I inserted Snow Leopard in Judy's MacBook Pro, and it opened the installation page. Luckily, I did not proceed with the installation then.

I called Apple support. First tech person discovered that there is a problem with early MacBook Pros and Snow Leopard. He referred me to another "product specialist" who was sure the problem was with later MacBook Pros, not our March, 2006 models.

At the Somerset Apple Store the Genius gave me great news. The problem is with some early MacBook Pros. If I understand correctly, these models have a single-layer DVD reader and Snow Leopard requires a dual-layer one. The solution was easy, the Genius told me. He would install Snow Leopard from an external Apple store DVD drive.

We thought that installation went fine, but in fact over 850 addresses failed to install. When I told the Genius about this the next day when I took Judy's MacBook Pro in for SL installation, he told me how to recover my addresses either from the Previous Address Book or from my Super Duper back-up. So if you take your MacBook Pro in for SL installation, you may save yourself a trip by taking in your back-up drive and checking Address Book before you leave.

I tried the Genius' advice and was overwhelmed with the richness of choices and the paucity of my knowledge. Today on my third trip to Apple Somerset this week another Genius found no sign of the Address Book on my computer. He found the addresses on my external back-up drive and installed them.

Thanks to all of you who have said over and over until I heard you: Back up everything on your computer. I felt moderately secure when I discovered most of my Address Book was missing because I had a SuperDuper back-up in an external hard drive in a bank safe deposit box and a second back-up drive at home. I doubt that I would have had such thorough back-up systems without the advice several long-time MacGroup members have given over and over and over! Thanks.

If you have a MacBook Pro, early vintage, it may open SL, as Judy's did. Mike's advice when he learned Judy's MBP was same age as mine: bring it in for an installation. It will install half of SL, tell you it will re-start, but it won't complete the installation. My advice: if in doubt, go to the Genius Bar. They know what is going on.

I don't know whether anyone with Apple can tell you by phone whether your model of MacBook Pro will require help. There may be a firmware update to fix this problem, one Genius guesses. Until that happens, if you have any problems with SL installation, I suggest you head for Apple Somerset where the Genius Crew knows what to do with early MacBook Pros.

And how do we like our upgrade from Tiger to Snow Leopard? After a few hours with Snow Leopard we are satisfied with it and relieved that it is on and working. We have not yet got into many of its features we have read about.

This message has been edited. Last edited by: David Snider,