title: Unable to access documentation in visual studio 2008
body: <p>The documentation system in my VS2008 installation seems to have become corrupted. Neither the Help-Contents window not the Help-Index window display anything apart from the Filter popdown (which seems to be empty) - and if I try to use this popdown I get a the error message</p>
  
  <p>"The selected filter contains an error that prevents it from being applied"</p>
  
  <p>There must be some corrupted index somewhere - any suggestions for a resolution?</p>