A regular IISReset /Restart turned into forcing a reboot. The stop worked but the start was unable to succeed.

The message was:

"Cannot start a new login session with an id that is already in use"

IISReset /Start reported the same problem.

NET STOP W3SVC reported the same problem.

In hope of finding the proper svchost.exe to terminate, I ran "tasklist /svc" but was unablet to see W3SVC among the tasks handled by one of the svchost.exe instance.

So, the last resort was to force a reboot.

Anyone has seen that one before or would know how we could have resolved that in a smooth way?