title: Permanent solution for windows installer Error 1500
body: <p>There is a very bad error telling you that another application is installing, when theres no such installation going on actually, and this error keeps coming after restart.
  There is a solution but for every install involving deleting the registery key Inprogress, and stopping and starting the installer service, you have to do this which is really bad.
  So, is there any permanent solution to this ?
  <a href="http://www.appdeploy.com/msierrors/detail.asp?id=111" rel="nofollow">http://www.appdeploy.com/msierrors/detail.asp?id=111</a></p>