I recently got a kernel panic, re-installed Snow Leopard (10.6.4) and as a result had no administrator account. I reset the root or whatever and got through that problem. Now I go to re-install my applications through the DVD and instantaneously after I hit install it doesn't even begin installing and I get the message
"The installation failed. An unknown installation error occurred. The installer encountered an error that caused the installation to fail. Contact the software manufacturer for assistance."
No 10.6.4 disc will function with a Mac that came with 10.6.2 or earlier. 10.6.3 is the last "retail" release that is not system specific. You can upgrade to 10.6.8 with a combo update if it presently is functioning. For a full listing of available updates, see my user tip: https://discussions.apple.com/docs/DOC-2455