So I was having this seriously frustrating problem where Visual Studio 2008 would lock up whenever trying to edit an .aspx page. Or a .master page. This was after I had installed latest Office 2010 Beta. Well after digging around, I found this helpful blog post… http://geekswithblogs.net/hinshelm/archive/2009/07/19/office-2010-gotcha-2-visual-studio-2008-locks.aspx
I followed the instructions and thankfully it worked. The instructions are basically to “Repair” the “Microsoft Visual Studio Web Authoring Component” found here… C:\Program Files (x86)\Common Files\microsoft shared\OFFICE12\Office Setup Controller\Setup.exe