How to: Create a Workflow Activity Library (Legacy)
Follow these steps to create a Workflow Activity Library project using the legacy Windows Workflow Designer provided by Visual Studio 2010. Use the legacy Workflow Designer when you need to target either the .NET Framework version 3.5 or the .NET Framework 3.0.
To create a workflow activity library project
Start Visual Studio.
On the File menu, point to New, and then select Project.
The New Project dialog box opens.
Select either the .NET Framework 3.0 option or the .NET Framework 3.5 option in the drop down list at the top of the New Project window to access the legacy designer.
Note: The default option in Visual Studio 2010 is .NET Framework 4. This option is used to create Windows Workflow Foundation (WF) applications that target the .NET Framework 4 and it does not use the legacy designer.
In the Project Types pane, select Visual C# or Visual Basic (under Other Languages) and then select Workflow.
In the Templates pane, select Workflow Activity Library.
In the Name box, enter a descriptive name for your project to make it easy to identify.
In the Location box, enter the directory in which you want to save your project, or click Browse to navigate to it.
If you want a solution directory created for the project, select the Create directory for solution check box and enter a name in the Solution Name box.