Could you please update us with the below information ;
What is the computer ‘s operating system ?
How is the computer connected to Internet ? (dsl/wireless/cable)
Do you currently have any other seeucirty software running along side McAfee ? OR anything in the past ?
Both computers are running Windows XP Professional SP3. One is connected by hardwired ethernet directly to my router and then via a cable modem to the internet. The other is connected wirelessly through the same router/cable modem. Neither of these computers has had any other security SW installed other than McAfee. The last update for both went OK. It's just not a stable or realiable process.