I had no troubles intalling BlogEngine 1.5 on IIS 6, but then I needed to install it on IIS 7 and was getting 500 error when trying to access it.

2 steps to solve this issue:

  1. In web.config file, remove system.webServer node
  2. Change application pool BlogEngine is running under to Classic .NET AppPool
    1. You should be able to connect to BlogEngine without problem now

If you want to use IIS 7 application pool and not Classic .NET AppPool

  1. Run this command %systemroot%\system32\inetsrv\APPCMD.EXE migrate config "WebSiteName/VirtualDirectoryName"
    1. WebSiteName = name of the website you've installed blog under
    2. If you used Virtual Directory, specify WebSiteName and VirtualDirectoryName, otherwise specify web site name only
  2. Change application pool from Classic .NET AppPool to IIS7 one