I installed Office 2010 on my development machine a few weeks ago. I didn’t realize that this was relevant to the problem I’ve been fighting in Visual Studio 2008 until today. The basic problem was that any time I opened an .aspx file, Visual Studio would lock up. It made making any web edits impossible and I’ve been having to edit these files in a different text editor.
I’d tried resintalling the last Service Pack without fixing the issue. So today I sat down to search for the problem and found and article called Upgrade or Uninstall of Office 2007 might cause VS 2008 Web designer to hang. The issue it turns out happens when you upgrade from Office 2007 to Office 2010 on a computer running a 64 bit OS with Visual Studio 2008. It turns out that Office 2007 and Visual Studio 2008 share the web editing component and when you do the upgrade to Office 2010, the component that VS 2008 relies on is removed.
The fix is to go into Program and Files, click Change on the Microsoft Visual Studio Web Authoring Component, and then select Repair. Once that’s done Visual Studio 2008 will work as before.