In case you’re having an issue watching Netflix through Windows Media Center because of an “Authorization failure…” error, try the following (it worked for me):
1. Exit Media Center.
2. Open Internet Explorer and click Tools and then Internet Options.
3. Click the Delete button – check all of the check-boxes and then click the Delete button. Click OK.
4. Browse to http://www.netflix.com and sign in. Note: No need to save the passwords in IE.
5. Close Internet Explorer.
6. Open Netflix and play anything.
7. Click Yes to the pop-up.
That’s it. Hope it works for you like it did on mine.