While enabling IIS on Windows 8 RTM, it prompted me for retrieving files from Windows update, so I clicked it and kept getting stuck with windows error 0x800F0906.
The answer is simple, thanks to this Technet thread. You basically have to do the following:
1. Mount your Windows 8 image, take note of the drive letter
2. Open command prompt with administrator privileges and run the following command, replacing the <drive_letter> with your win 8 mounted image drive letter:
dism.exe /online /enable-feature /featurename:NetFX3 /Source:<drive_letter>:\sources\sxs
For example, if your drive letter is G, then the command above would look like:
dism.exe /online /enable-feature /featurename:NetFX3 /Source:G:\sources\sxs
This would first install .NET 3.5, after the operation has completed you can go back to control Panel > Programs > Turn windows features on or off and happily enable IIS.