The vcenter server cannot be started because port 80 of IIS is used up.

When I came back from Nanjing on a business trip, I found that I couldn't connect to the vcenter server with VI Client and connected to the vcenter with a remote desktop. It turned out that the vcenter service was not started. I found that the service could not be started manually and reported an error.
Check the vcenter server log and find the following sentence:
Failed to create http proxy: Resource is already in use: 0.0.0.0: 80
The IIS service in windows runs and occupies port 80. As a result, the vcenter service cannot be started, the IIS service is stopped manually, The vcenter server service is restarted, and the VI Client is reconnected successfully.

Author: "star & storage"