IIS Error: It is being used by another process

While maintaining a server today, I tried to start a website, but I kept getting the error: “The process cannot access the file because it is being used by another process.”

Online sources suggested that this issue occurs because the port is being used by another program. So, I tried entering the following command in the command prompt:

netstat -obna

This allowed me to check the usage of various ports on the server. I found out that an FTP service was occupying port 80. I promptly disabled this service, restarted the website, and everything worked smoothly!

Reference: http://www.cnblogs.com/eagle1986/archive/2010/01/17/1649908.html