Thanks j.v., I rather thought that might be the problem. I am currently working on a hard disk from my previous MacBook Pro with OS 10.5.6 that died on me after only 1.4 years use (a logic board failure I was told by a Mac agent in Nairobi). I've had the HD converted to a USB plug-in to my new MacBook Pro. I restart my computer using that old hard disk so I can access the Internet, but it is most inconvenient not being able to exchange emails and surf the Net (I download a lot) and, as I just realized, update Norton and other software on my new Snow Leopard hard disk.