Right, this is weird.

In My Computer > Network Connections, when I click on Internet Connection to view the status of the connection, the little window that should appear opens - but only for about one tenth of a second before automatically closing itself again.

I don't know why it's doing this, I have tried Norton Antivirus, Microsoft Antispyware, Spybot, AdAware and Avast and apparently I'm clean.

Any ideas? Thanks