Today I've tried to start the Visual Studio Developer IIS as usual on Port 80, but this time it has quit with an error that port 80 is already in use. With netstat I've found out, that an application C:/Windows/System32/ntoskrnl.exe is using port 80. My OS is Windows 7 Prof. SP 1.
Has anyone an idea why this application is blocking port 80? Testing ntoskrnl.exe on https://www.virustotal.com/ has found no infections.