I had a problem with Visual Studio 2008 locking up when I would open an .aspx page for editing.  I run Process Explorer all the time, I want to know why the OS is slow, and it showed me that Microsoft Setup Bootstrapper in Office 2007 was running.  After doing several searches over several days, I found this great link to fix the problem: Visual Studio 2008 Locks or Freezes in ASPX.