How to make a change in iis apppool using appcmd.exe
I never use appcmd.exe but you could do this:
appcmd.exe set config -section:system.applicationHost/applicationPools /[name='DefaultAppPool'].enable32BitAppOnWin64:"True" /[name='DefaultAppPool'].managedPipelineMode:"Integrated" /[name='DefaultAppPool'].startMode:"AlwaysRunning" /commit:apphost
appcmd.exe set config -section:system.applicationHost/applicationPools /[name='DefaultAppPool'].processModel.identityType:"LocalSystem" /commit:apphost
In PowerShell using the WebAdministration Module:
Set-WebConfigurationProperty -pspath 'MACHINE/WEBROOT/APPHOST' -filter "system.applicationHost/applicationPools/add[@name='DefaultAppPool']" -name "enable32BitAppOnWin64" -value "True"
Set-WebConfigurationProperty -pspath 'MACHINE/WEBROOT/APPHOST' -filter "system.applicationHost/applicationPools/add[@name='DefaultAppPool']" -name "managedPipelineMode" -value "Integrated"
Set-WebConfigurationProperty -pspath 'MACHINE/WEBROOT/APPHOST' -filter "system.applicationHost/applicationPools/add[@name='DefaultAppPool']" -name "startMode" -value "AlwaysRunning"
Set-WebConfigurationProperty -pspath 'MACHINE/WEBROOT/APPHOST' -filter "system.applicationHost/applicationPools/add[@name='DefaultAppPool']/processModel" -name "identityType" -value "LocalSystem"
in both cases you need to replace the name DefaultAppPool
with the real name.
I hope you have very good reasons to run your pool as System, I would never do that.