Install and Configure LEADTOOLS Medical Web Viewer - HTML5 JavaScript

This tutorial shows how to install and configure the LEADTOOLS Medical Web Viewer.

Summary This tutorial covers how to install and configure the LEADTOOLS Medical Web Viewer
Completion Time 30 minutes
Platform JavaScript Web Application
IDE Visual Studio 2017, 2019, Visual Studio Code - Client
Development License Download LEADTOOLS

Required Knowledge

Before working on the Install and Configure LEADTOOLS Medical Web Viewer - HTML5 JavaScript tutorial, complete the Install and Configure LEADTOOLS Medical Web Service tutorial.

SQL Server


At least SQL Server Express 2005 or newer is required for this application.

By default, the LEADTOOLS configuration demos configure the LEADTOOLS Windows services and web services to run as the LocalSystem (NT Authority\System) identity. This is a special built-in account that has full access to the local system. SQL Server 2008 R2 and earlier included this account as a login with full access to SQL Server. Microsoft considered this a security flaw and the login was removed from the newer versions of SQL Server. For more information about creating a login, refer to the Microsoft topic, SQL Server – "Create a Login", at:

If enabled in SQL Server, SQL Server authentication can be used. If using SQL authentication, before running the LEADTOOLS Database Configuration demo, the SQL login must already exist. When adding the SQL login, make sure that the option "Must change password" is unchecked (cleared). Once the SQL login and user is created, connect to the database engine in Visual Studio or SQL Server Management Studio to test.

Use either Windows or SQL authentication to log into SQL Server. The mapped user must have the correct permissions to perform the functions required by the configuration tools and demos. For development, associating the user with the sysadmin server role and the dbowner role is the quickest but is not recommended for production due to obvious security concerns.

Using Windows authentication requires a Windows user account, a SQL login for the Windows user account, and a SQL user account mapped to the SQL login associated with the Windows user account.

Ensure the Windows user account is set up with access to the following items:

Microsoft Typescript

Although TypeScript is not required to run the LEADTOOLS HTML5 Medical Web Viewer Demo, it is highly recommended in order to modify the JavaScript code that calls the LEADTOOLS web services.

For more information, refer to:

IIS Features

IIS with at least the following features is required (Select ALL options under each section):

For Windows 8 or newer the following features are required: .NET Framework Advanced Services


In Windows 8 / Server 2015 and newer, be sure to select version 4.7.

Open the Windows Start menu and start typing "Turn Windows features on or off". Open the Windows Features dialog box and make the following selections (both a listing of the selections and screenshots of the selections within the dialog box are provided below):

Set the License File

The HTML5 Viewer requires that a LEADTOOLS.lic.txt file be placed into a sub-folder in the Members directory. Adding this license file will remove the Nag Message seen by the client. This LEADTOOLS.lic.txt file is generated separately from the LEADTOOLS.LIC and LEADTOOLS.LIC.KEY files. Note that the LEADTOOLS.lic.txt file cannot be created based on either of those files. This file must be generated by the LEAD Sales department and be provided to you. After you receive the file, create a folder called "LEADTOOLS" in the following directory:


Inside the "LEADTOOLS" folder, add the LEADTOOLS.lic.txt file. The following file should now exist:


If there is any question about where the code is searching for the LEADTOOLS.lic.txt file, simply open the browser's JavaScript debugger and check the console to determine where the viewer is searching for the LEADTOOLS.lic.txt.

Required Runtimes

The LEADTOOLS kernel module (for example Leadtools.dll for .NET) is required for applications.

LEADTOOLS binaries for .NET require the Microsoft Visual C++ 2017 Runtime. The Microsoft Visual C++ 2017 Redistributable Package cannot be installed on some versions of Windows. For supported versions, see Choosing a Deployment Method and Update for Universal C Runtime in Windows. The Microsoft Visual C++ 2017 Runtime also requires the Windows Universal CRT library, which is distributed as part of Windows 10. For information on how to redistribute the universal CRT, see Introducing the Universal CRT.

The file names are the same for Win32 and x64. However, the actual binaries are different. For more information about distributing the Microsoft C/C++ runtime files, refer to:

Directory Structure

The entire Medical Viewer project can be found in the <LEADTOOLS_INSTALLDIR>\Examples\Viewers\DotNet\MedicalWebViewer\MedicalWebViewerDemo folder.

Steps to Configure the Medical Web Viewer

Perform the following steps to configure the Medical Web Viewer:

  1. Browse to the <LEADTOOLS_INSTALLDIR>\Shortcuts\Medical Viewer\JavaScript\Medical Web Viewer folder.

  2. This step varies, depending on the version, as follows:

    • Run the "Run This First to Run the Medical Web Viewer 32-bit Demo" when using the 32-bit demo.
    • Run the "Run This First to Run the Medical Web Viewer 64-bit Demo" when using the 64-bit demo.
  3. A dialog similar to the following figure, stating that the databases are not configured, may be displayed. Click the Yes button to configure the database.

    PACS configuration demo message box.
  4. The Database Configuration Demo will attempt to enumerate the SQL Servers available on the network. If the demo was unable to enumerate the SQL Servers, it may display a message box similar to the following figure:

    Database configuration wizard message box.
    • If it does, click OK.
  5. The configuration manager will find all the SQL Servers it has access to on the network and set one of them to the default. Change the default SQL Server by clicking the Change button underneath the Databases section. The configuration application will scan for available databases and present the options in the dropdown menu. Then choose either Window Authentication or SQL Server Authentication to connect to the server. Click OK to save the new options.

    Change databases dialog box.
    Create LEAD storage server database.
  6. Choose from the database options. Create a new database or connect to an existing database. Enter the User Name and Password for the application. This will be the User Name and Password to log into the Medical Web Viewer once it is running. Once these settings have been adjusted as desired, click the Configure button on the bottom left.

    New database with username and password.
  7. A dialogue box will appear summarizing the options made from the previous window. Click the OK button to confirm.

    Connection summary message box.
  8. The application will configure the databases and display its progress in the Status window.

    Configuration status in the status window.
  9. When the application completes the SQL Server set up, a Configuration is successful! message will appear in the Status dialogue box. Click the Close button to continue.

  10. After configuring the SQL Server the demos have to be set up. A Help window will appear explaining the optional and required settings for the demo application. Read through the options listed and click OK when ready.

    Demo help message box.
  11. Review the settings listed under DICOM Servers Settings and DICOM Client Settings. When the settings are configured as desired, click the Configure button to create the DICOM services and configure the client demos.

    Configure the DICOM server and client settings.

    The Status window will display the progress of the configuration application as it sets up the demos.

  12. After all services are installed, the demo then tries to communicate with the SQL Server instance through each service. If any of the services fail this test, follow the steps detailed in the SQL Server with Windows Authentication section. To complete the configuration, run the following utility from the <LEADTOOLS_INSTALLDIR>\Examples\Viewers\DotNet\MedicalWebViewer\WebViewerConfiguration folder:

    • Run the "Run This Second to Run the Medical Web Viewer 32-bit Demo" when using the 32-bit demo
    • Run the "Run This Second to Run the Medical Web Viewer 64-bit Demo" when using the 64-bit demo

    The selected utility loads and is shown in the following figure:

    Medical Web Viewer configuration dialog box.
  13. Click the Fix Problems button to complete the configuration. If the demo displays an IIS warning, make sure you have all the IIS Prerequisites. Then, restart the Medical Web Viewer demo and try again.

  14. The LEADTOOLS Service Host Manager will start. Accept the default settings and click Next to proceed through the Service Group and Setup tabs. The tabs are shown in the following figures.

    LEADTOOLS services host manager service group tab.
    LEADTOOLS services host manager setup tab.
  15. The LEADTOOLS Service Host Manager will next create an Application Pool named LEADTOOLS_DOTNET_v40, and three IIS applications, as follows:

    • The MedicalViewerService22 application hosts the LEADTOOLS WCF service classes as web services.

    • The MedicalViewerServiceAsp22 application hosts the LEADTOOLS Asp.Net service classes as web services.

    • The MedicalViewer22 application hosts the LEADTOOLS HTML5 Medical Web Viewer demo application files.

  16. In the Status tab, click the Test All button, then follow any troubleshooting links and make any required adjustments. You should see a screen like the following:

    LEADTOOLS services host manager status tab.
    • Continue to click Test All until all issues are resolved. The status tab is shown in the following figure.
  17. If you are using SQL Server with Windows Authentication, perform the following steps to login to the demo.

    • Open the IIS Manager.

    • Highlight the LEADTOOLS_DOTNET_v40 in order to prompt additional Actions to become available.

    • Click Advanced Settings in the Edit Application Pool section of the Actions panel, as shown in the following figure:

      IIS manager application pools advanced settings.
    • In the Advanced Settings dialog box, click Identity in order to open the drop-down list, as shown in the following figure:

      IIS manager advanced setting identity.
    • Select the Custom Account radio button and then click Set, as shown in the following figure:

      Application pool identity set custom account.
    • In the Set Credentials dialog box, fill out the User Name and Password, using the ones that will be used for validation. The dialog box is shown in the following figure:

      Set custom account credentials.

Run the Project

You should now be able to navigate to the link shown in the screenshot in Step 16. Login using the credentials set in Step 6. At this point the LEADTOOLS Medical Web Viewer demo is fully functional and you can begin your testing. You should see the default login page load.


This tutorial showed how to install and configure the Medical Web Viewer to load and view patient studies.

See Also

Help Version 22.0.2024.3.20
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© 1991-2023 LEAD Technologies, Inc. All Rights Reserved.

Products | Support | Contact Us | Intellectual Property Notices
© 1991-2023 LEAD Technologies, Inc. All Rights Reserved.