Unable to change network - menu gone

Hello,
I have an HP laptop running Vista with SP1 (installed successfully after several hours with a Microsoft Technical support person). Recently I took my laptop with me on a trip to N.Z. and found that I am unable to change from my home network, because the menu does not come up. When I click on the 'Connect To' menu item from the Start button, nothing happens. Ditto when I right-click on the network icon on the right-hand side of the task bar, and choose 'Connect to a network'. Nothing happens at all. This used to work fine (before the Service Pack was installed). I am assuming it was the service pack installation that caused the problem, because the support people disabled all the start-up applications to determine what was causing the problem with its installation, but I can't prove this as I haven't tried to change the network for the several months since this occurred, and I'm not sure what was disabled (or how to re-enable it), especially seeing as the network stuff at my house works fine. I am thinking that I may have to reload Vista, but I don't have a complete copy of the s/w with all the updates including SP1, so would rather not have to go that route.
Thanks for any assistance.