After some failed attempts at stopping and starting servers through third party tasks, I had quick success using the exec command in the TFSBuild.proj:

<PropertyGroup>
    <web-site-id>1</web-site-id>
    <server-cmd-prefix>C:\Windows\system32\cscript.exe c:\Inetpub\AdminScripts\adsutil.vbs</server-cmd-prefix>
    <stop-server-cmd-line>$(server-cmd-prefix) STOP_SERVER W3SVC/$(web-site-id)</stop-server-cmd-line>
    <start-server-cmd-line>$(server-cmd-prefix) START_SERVER W3SVC/$(web-site-id)</start-server-cmd-line>
 </PropertyGroup>
  
 <Target Name="StopSite">
    <Message Text="stopping site..."/>
    <Exec Command="$(stop-server-cmd-line)"/>
 </Target>

 <Target Name="StartSite">
    <Message Text="starting site..."/>
    <Exec Command="$(start-server-cmd-line)"/>
 </Target>

Labels: .Net, TFS