Connection problems!?

Have just switched to Sky wireless broadband from BT wireless broadband today. Laptop connection working great but PC connection not working. Have checked all the connections as per Sky recommendations (ie LAN settings, web browser settings, etc). If I do get connected it will display the Sky homepage but I cannot surf any furrther than this - always comes up "Cannot find server". Also when I go to shut down the computer the following 'end program' screens come up: "Hsm sink window", Connections tray" and "explorer.exe". Am having problems also in the Network connections window - when I right click on any of the connections (eg LAN) it takes forever for the dialogue box to come up and the computer has frozen on loads of occasions and I have had to switch off the computer manually. I know there are a lot of queries in this but any advice would be much appreciated as these problems have only started since I switched my broadband today. Thank you in anticipation.