Visual Studio WinForm program cannot add a reference to System.Web

Visual Studio WinForm program cannot add a reference to system.web [reprint]

Need to refer to system.web. Found no "system.web". After finding the DLL reference through the Browse method, it is found that an exclamation mark appears.

Toss the long time, noting that the current frame used by the error hint is ". Net Framework 4 Client profile", it seems that this is the new division in VS 2010 (in the previous version, but there is no "Client" this stuff), The Item Purpose property Page is opened and the target framework under application is selected as ". Net Framework 4".

Visual Studio WinForm program cannot add a reference to System.Web