Here's the situation: I have an old 800 mhz imac (dome) that I am going to sell. I wiped/loaded a clean install of Leopard 10.5 on it. I clicked the software update and get this message (fairly quickly): "A networking error has ocurred. The operation could not be completed. (NSURLErrorDomain error - 1100) (-1100) Make sure that you can connect to the internet, then try again." I googled it but no help. So, I went to Apples site and downloaded the combo update for 10.5 - 10.5.6 (668 MB total) When I mount it and run the installer, I get to the part where I select the volume.. and theres an exclamation point over the (only) volume. So I cant' install the update either!!! The error reads: "You cannot install Mac OS X Update Combined on this volume ERROR_INSTALL" I've deleted the Software Update preference file. I could use a little advice - thanks.