Installing GRR clients on Windows

For Windows you will see a 32 and 64 bit installer. Run the installer as admin (it should load the UAC prompt if you are not admin). It should run silently and install the client to c:\windows\system32\grr\%version%\. It will also install a Windows Service, start it, and configure the registry keys to make it talk to the URL/server you specified during repack of the clients on the server.

The Windows clients are special self extracting zipfiles. Just double click or otherwise execute the binary. If you are not an administrator it will prompt you for credentials. It should then install silently in the background, unless you enabled the verbose build.

The most straightforward way to deploy a GRR client to a Windows machine is to use PsExec. PsExec allows one to execute commands on a remote system if credentials for a valid user are known.

To do so, start by downloading psexec and placing in a directory of your choice, we’ll call it CLIENT_DIRECTORY here. Store the version of the client you want to download to the same directory.

Once you have both, you have to make sure you know the username and password of an Administrator user in the remote system. Once all these requirements are met, just start a cmd.exe shell and type:

psexec \\MACHINE -c -f -s client-version.exe

Note: The NET USE command will ask for a password interactively, so it’s not suited for using in scripts. You could Switch the * for the PASSWORD instead if you want to include it in a script.

You’ll need to replace:

  • C:\CLIENT_DIRECTORY\ with the full path you chose.
  • MACHINE with the name of the target system.
  • USERNAME with the user with administrative privileges on the target system.

This will copy the client-version.exe executable on the target system and execute it. The installation doesn’t require user input.

The expected output is something along these lines:

C:\> net use \\\IPC$ /USER:admin *
Type the password for \\\IPC$:
The command completed successfully

C:\CLIENT_DIRECTORY> psexec \\ -c -f -s client.exe
PsExec v1.98 - Execute processes remotely
Copyright (C) 2001-2010 Mark Russinovich
Sysinternals -

The command completed successfully.

client.exe exited on with error code 0.


For even less footprint on installation you could host the client on a shared folder on the network and use this psexec command instead:

psexec \\MACHINE -s \\SHARE\FOLDER\client-version.exe

This requires the USERNAME on the remote MACHINE be able to log into SHARE and access the shared folder FOLDER. You can do this either by explicitly allowing the user USERNAME on that share or by using an Anonymous share.

The best way to verify whether the whole installation process has worked is to search for the client in the GUI.

Uninstalling on Windows

On Windows the client does not have a standard uninstaller. It is designed to have minimal impact on the system and leave limited traces of itself such that it can be hidden reasonably easily. Thus it was designed to install silently without an uninstall.

Disabling the service can be done with the Uninstall GRR flow, but this does not clean up after itself by default.

Cleaning up the client is a matter of deleting the service and the install directory, then optionally removing the registry keys and install log if one was created.

On Windows, GRR lives in


The service can be stopped with

sc stop "grr monitor"

Or via the task manager.

The GRR config lives in the registry, for a full cleanup, the path


should be deleted.

Removing the GRR client completely from a machine:

sc stop "grr monitor"
sc delete "grr monitor"
reg delete HKLM\Software\GRR
rmdir /Q /S c:\windows\system32\grr
del /F c:\windows\system32\grr_installer.txt