Microsoft banned from my computer? (virus?)

[Green Devil]

The strangest thing has happened to both my computers (same IP address). Since this morning, I cannot log to Windows Live Messenger or visit any website related to Microsoft. I have no problems browsing the net, but if I try to visit msn.com, microsoft.com or click on any banner that has with microsoft to do, the page just won't load.

Can anybody help?

Thanks.