This step-by-step guide for installing the Windows Integration Service (WIS) assumes that you already have the SDK downloaded. To start, you will need the **CommerceIntegrationServiceSetup.msi** file which can be found in the **\\WindowsIntegrationService\\x64** folder (or the **\\WindowsIntegrationService\\x86** folder for the 32-bit version) of the SDK.
If you are running **Windows Defender SmartScreen**, you may need to override the security warning by selecting **Show More** and then selecting **Run Anyway**.
Double click to open the **CommerceIntegrationServiceSetup.msi** and click **Next**.
Choose the file path to install the integration service. Optimizely recommends using the default path.
Prior to installing the Integration Service on the default C: location, review the amount of available disk space. If the disk space is limited, choose a new location. Low disk space can possibly bring down your server due to large log.tx files and their respective backups.
Then click **Next**.
After the installation has completed, click **Finish**.
## Start the WIS
Prior to starting the Integration Service, a connection must be configured. See the [Configuring the WIS article.](🔗)
To start the **Integration Service**, follow the steps below:
Click **Run**. (If you do not see the run command in your start menu, you can search for it.)
Once **Run** has opened, enter **services.msc** and click **OK**.
Locate **Commerce Integration Service** **4.2** from the list and right click it.
Select **Start** from the menu.
Once these steps have been completed, the service should show that it is running. You can now go to the folder where you installed the WIS and review the logging in the logfile.txt to address any errors. If connection information isn't set up correctly, this logfile.txt will alert you of problems encountered.