In Windows, it is possible to deploy Splunk using msiexec. This makes it much easier to automate deployment on a large number of machines. To install silently, you can use the combination of AGREETOLICENSE and /quiet, as follows:
msiexec.exe /i splunk-xxx.msi AGREETOLICENSE=Yes /quiet
If you plan to use a deployment server, you can specify the following value:
msiexec.exe /i splunk-xxx.msi AGREETOLICENSE=Yes DEPLOYMENT_SERVER="deployment_server_name:8089" /quiet
Or, if you plan to overlay an app that contains deploymentclient.conf, you can forego starting Splunk until that app has been copied into place, as follows:
msiexec.exe /i splunk-xxx.msi AGREETOLICENSE=Yes LAUNCHSPLUNK=0 /quiet
There are options available to start reading data immediately, but I would advise deploying input configurations to your servers, instead of enabling inputs via installation arguments.