How to use

All you need to do is:

add the "RunAs" TeamCity Build Feature or use the advanced options "Run as" of any build step
specify the user name for RunAsUser. For Windows the following formats are acceptable: username or username@domain or domain\username
specify the password

For example

That's it! Once the build is run, the plugin runs all commands under the specified Windows user account.

For agents under the Windows OS you could also specify Windows Integrity Level, logging level and additional arguments.

Implicit mode

Sometimes there is a case when all build steps on a TeamCity agent should be runned under the specific user account by default:

You could disable UI extensions for runAs plugin, if it is needed, via TeamCity server parameters. For example using the -Dteamcity.runas.ui.enabled=false command line argument
Configure runAs tool settings using the TeamCity configuration parameters or in the file buildAgent\conf\buildAgent.properties for each build agent: run_as_user - for user name, secure:run_as_password - for password and run_as_additional_args - for additional command line arguments for runAs tool. For example the file c:\buildAgent\conf\buildAgent.properties may contain the following additional lines:

run_as_user=MyUser

secure\:run_as_password=MyPassword

Note that the symbol ":" should be escaped by the symbol "".