Unable to connect to the network

My phone has gone haywire in the last 24 hours, i called into the phone shop and they suggested i do an online software update. I clicked onto the update service but then it said that it was unable to connect to the internet. I'm on the internet now but it still won't get through to it for me, i've also ensured that my firewall and virus protection allow the update service. I don't know why it won't work.
Any suggestions are kindly appreciated