I presume that your new PC is running XP, and your old one is not.
There are several differences that come with XP that may be contributing to the problem -
1. IE6 - XP comes with IE6, which has a higher level of security set as default than previous versions of IE
2. Firewalls - XP has a built-in firewall
3. DirectX 8 - comes as standard with XP.
Any or all of these settings may be contributing to the symptoms that you describe. Without your new PC at home, it is not possible to check what your current settings are.