Grouchen!
Often it's worth trying again later, or even the next day, and you could find it's OK.
If not, and if Sandra's suggestion isn't sucessful, do you know how to clear your Temporary Internet Files and Cookies? This often works wonders to clear blockages to certain websites.
In Internet Explorer, open the 'Tools' menu, then 'Internet Options'. You should see two buttons, 'Delete Files', and 'Delete Cookies'. Click each of them, then 'OK' to confirm. It does mean you'll have to log in again to any websites that 'remember' you, so make sure you know your user name & passwords to any sites where your details are stored, i.e. shopping sites, forums, etc.
Hope that helps!