Norton Internet Security 2009 is experiencing real problems with configuring updates

My Norton Internet Security 2009 is experiencing real problems with configuring updates. At the moment it is booting, then showing me it is configuring updates Stage 3 of 3 at 0% complete. It shuts down every five minutes, reboots and shows the same information i.e. configuring updates Stage 3 of 3 at 0% complete. It sits on an Acer Aspire 5570 running Windows Vista Home Premium. Any clues