You can use appcmd list sites to get a list of sites and identifiers.
Open a command prompt using Run as Administrator.
C:\WINDOWS\system32\inetsrv>appcmd list sites SITE "Default Web Site" (id:1,bindings:http/*:80:,state:Started) SITE "Site1" (id:2,bindings:http/*:80:site1.com,state:Started) SITE "Site2" (id:3,bindings:http/*:80:site2.com,state:Started)
To find a site by name, use appcmd list site "SiteName":
C:\WINDOWS\system32\inetsrv>appcmd list site "Default Web Site" SITE "Default Web Site" (id:1,bindings:http/*:80:,state:Started)
To find a site by id, use appcmd list site -id:N:
C:\WINDOWS\system32\inetsrv>appcmd list site -id:1 SITE "Default Web Site" (id:1,bindings:http/*:80:,state:Started)
Note: appcmd will still work as a non-admin, but will display "state:Unknown".