ClickOnce deployment is available only in Visual Studio 2005 and only for Windows applications.

ClickOnce reduces the time and effort required to deploy Windows applications across a network. Rather than distribute a separate executable to each individual hard drive, ClickOnce places the executable on a common Web page, from which all users can launch it. As part of the launch process, a copy is retrieved to the user's hard drive that can be used to re-launch the application locally. However, this local copy regularly checks the source executable on the Web page for updates.

Updates to the Windows application can be re-published to the Web server, and the newer application files are then available to clients. If an older version of the Windows application opens locally on a client machine, an update dialog box gives the option to check for updates from the Web server.

To publish the Windows application, you use the Publishing Wizard to choose a Web Site address. The published Web Site contains hyperlinks to the Windows application installer and the ClickOnce deployment online help. If you have set the prerequisite properties, the Web Site also has a link to the prerequisite files.

To publish a Windows application
- In the Solution Explorer, right-click the bold project name, and click Publish.
- When the Publish Wizard dialog box appears, click Next.
- In the Will the application be available offline? dialog box, select Yes, this application is available online or offline, and then click Next.
- From the Ready to Publish! dialog box, note the URL where the application is published, and then click Finish.

To complete ClickOnce deployment, open the published Web Site and choose the option to install the Windows application.

To install and run the Windows application on a client machine
1. On the client machine, open a Web browser window.
2. In the browser's address bar, type the URL of the published Web Site that you have created in the previous procedure.
The published Web Site displays the name of your Windows application.
3. The Web Site contains links to install and run the Windows application with the prerequisites or without the prerequisites.
3.a) Click the launch link to run the application if you have already installed the prerequisites on the client machine.
3.b) Click the install link to install the prerequisites on the client machine and run the application.
From the Install Application dialog box, the Grant permissions and confirm installation message appears.

Note This message appears because you set the security property to FullTrust in the procedure S etting the ClickOnce Deployment Properties.
4. Click Install.

After the installation is complete, you can access the Windows application through the Start menu.

REFERENCES
1. MSDN Library.