I Have mac osx 10.5.8 and have tried to update to mac osx snow leopard 10.6.3, but I constantly get the install failed message. What could be the problem?

I'm not sure you can go straight from 10.5.8 to 10.6.3. The latter contains fixes and updates that may not be compatible with a direct upgrade from Leopard. Can you try a clean install after backing up your personal data?

Are all of the following true?

• You are using a retail copy of the Snow Leopard installer DVD (like this one), & not one that came with another Mac?

• Your iMac meets the minimum system requirements (as shown on the Apple Store web page)?

• You are following Apple's recommended method of installing Snow Leopard (as specified in the "Upgrading Mac OS" section of theInstallation & Setup Guide) exactly, for example by starting the process by double-clicking the Install Mac OS X icon while started up normally from 10.5.8?

• You have tried the steps in the "Installation Wasn't Successful" section of the Guide?

• The Snow Leopard installer DVD is clean & free of scratches?

If all of the above are true, you should have had no problems going directly from 10.5.8 to 10.6.3. If you did, are there any error messages shown besides "Installation Failed"? If not, open the Console app (in the Utilities folder) & look for an "install.log" in the "/private/var/log" section. Click on that & look for any errors it shows for the installation attempt.

Yes you can go to 10.6.3 direct from 10.5.8.

However, you need to be using the retail SL DVD;

If you are, and it won't install, how are you going about it?

You should boot from the Installer DVD by holding down the C key during start up until the Apple logo and spinning cog wheel appears. Allow plenty of time for the installer to appear - it can take several minutes when booting from a disc.

If you've attempted and got a partial install, check Finder for a folder called something like "Mac OS X Install Data".

If that's present, subsequent attempts will fail because installer 'thinks' the job is already done.

Other things to check - clean the disc carefully with a soft lint-free cloth from inside to out (not circularly) and check for scratches.

Apologies, R C-R; the forum seems to be playing silly b*****s again. Your post wasn't visible when I wrote that lot, in spite of being timed about a half-hour earlier.

noondaywitch wrote:

You should boot from the Installer DVD by holding down the C key during start up until the Apple logo and spinning cog wheel appears. Allow plenty of time for the installer to appear - it can take several minutes when booting from a disc.

I suggest not doing this unless the Apple recommended method (starting by double-clicking on the

Install Mac OS X icon while booted up normally) fails.

There are several reasons for this:

The Apple method performs a check of the DVD's integrity before starting up from it. This can't be done if you start up directly from the DVD.

The Apple method "phones home" using the current OS's network settings to check for updates to the incompatible items database included on the DVD & writes a lot of pre-install data (the 'Mac OS X Install Data' stuff) to the HD before restarting automatically from the DVD to finish the installation. This may not work as expected if you start up directly from the DVD.

The pre-install data on the HD speeds up the installation process (because running the OS from the HD to build the data is faster than doing that while running from a DVD).

The Apple method makes it possible to "gracefully" cancel the installation before the automatic restart occurs without leaving the existing OS on the HD in a corrupted, "half-installed" state unable to restart the Mac. This sometimes happens if the installation process hangs & one has to force-restart the Mac to recover. As long as this occurs during the "pre-install phase" before the restart, the existing OS should remain untouched & intact.

Also note that the Snow Leopard installer is quite a bit more sophisticated than the previous ones like for Leopard or Tiger. It automatically performs the equivalent of Disk Utility's Verify Disk step before beginning the installation & performs more checks during the installation process (including checking the pre-install data for errors). It is usually not necessary to remove the "Mac OS X Install Data" folder after a failed installation, which may just cause the process to take longer on subsequent attempts, but if nothing else helps it is certainly something worth trying.

noondaywitch wrote:

Apologies, R C-R; the forum seems to be playing silly b*****s again. Your post wasn't visible when I wrote that lot, in spite of being timed about a half-hour earlier.

No apology needed. I think the OP benefits from different users' replies, even if they contain duplicate info … or disagree on a few of the details. 😉