Are you using Internet Explorer? If you are then have a look at the Internet Options which is under "Tools" at the top of the window. If you're running version 6 of Internet Explorer, there should be a tab with Privacy on it. On that page there is a slider that allows you to control cookies, slide it down to Medium and click Apply then OK. Hopefully you should be able to get your .NET passport now. My memory is a bit vague about previous versions of IE, but if you explore the Internet Options tabs you should find cookie controls somewhere. Failing this, are you running a firewall? Some firewalls can be a bit over protective, try disabling it temporarily. Good luck.