Trying to build a document preview window in Sharepoint, I noticed that it is no longer possible to stream a Word document inside a browser window. This problem occurs when you use Office 2007 in combination with Internet Explorer 7 and is behavior by design. Microsoft decided on this behavior to increase overall security and usability.

But what if you really need to open the document inside the browser? There is only one way around; Microsoft published a KB about the issue which can be resolved by making changes to the registry which you can read here. If you have no control over the end-user’s computer you’ll probably have to find another solution like generating PDF previews. What a bummer…