Problem: Can’t install IIS
I tried to install IIS from “Turn Windows features on or off” but it shows me an error and IIS hasn’t been installed.
Environment: Windows Vista SP2
Cause: “Configuration APIs” and “Process Model” of Windows Process Activation Service (WAS) was disabled
IIS needs these components.
Some weeks ago, I removed them because I didn’t think I need them. When I removed these WAS components, I haven’t installed IIS, so no error messages are shown.
Solution:
Open “Turn Windows features on or off.” Then find “Windows Process Activation Service” and open the node. You can see three sub-nodes: “.NET Environment”, “Configuration APIs” and “Process Model.”
Check “Configuration APIs” and “Process Model.” and press OK to install them.
After the end of installation, open “Turn Windows features on or off” again and install IIS components.
(I guess you can install Windows Process Activation Service components and IIS components at the same time, but I’m not sure.)
When WAS and IIS components are both installed and uncheck WAS components to uninstall, you will see alert message. It says “some IIS components are dependent on this components. If you remove this component, those IIS components are also removed.”
Phanective Process 