Problem #

After upgrading to the Windows 10 Fall Creator. I got the message below when I tried to access my IIS site

Service Unavailable
HTTP Error 503. The service is unavailable.

and you may see the error below in windows event viewer:

Solution #

To solve the problem you can follow these steps:

1. Open a Windows PowerShell window by using the Run as administrator option.
2. Run these commands:

Stop-Service -Force WAS
Remove-Item -Recurse -Force C:\inetpub\temp\appPools\*
Start-Service W3SVC

For more detail, please refer to this link: https://goo.gl/uH8o9n