Quickly helping one of colleague where after restoring applicationhost.config from the back up on win2k8 IIS 7 we started receiving 503 Service Unavailable on the browser.
As the very first step was to check event viewer where we had the following logged:
Log Name: Application Source: Microsoft-Windows-IIS-W3SVC-WP Date: 7/28/2009 12:46:10 AM Event ID: 2280 Task Category: None Level: Error Keywords: Classic User: N/A Computer: <computer_name> Description: The Module DLL C:\Windows\System32\inetsrv\compdyn.dll failed to load. The data is the error.
compdyn.dll ==> Dynamic Compression
Checking the inetsrv folder we were not able to locate this dll.That’s interesting.
Option provided was to :
1) Either to turn off the dynamic compression in applicationhost.config
2) Or to install the dynamic compression modules from Add Role Services Wizard, select Dynamic Content Compression
Till then bye bye …