For debugging class libraries, web services etc., we may need to attach the debugger to a running ASP.NET process. 

It is better to write a macro to accomplish the above and use it for any number of times using a simple Key press (with your own key combination).  Following are the steps to achieve the same:

• Open Visual Studio 2005
• Press Alt-F8 to bring up Macro Explorer
• Add a new Module (AttachProcessToWeb) and type in the code as following:

Imports System
Imports EnvDTE
Imports EnvDTE80
Imports System.Diagnostics
Imports EnvDTE90
Imports System.IO
Public Module AttachProcessToWeb

    Public Sub AttachProcess()
        Dim process As EnvDTE.Process
        For Each process In DTE.Debugger.LocalProcesses
            If (Path.GetFileName(process.Name).ToLower() = "aspnet_wp.exe") Then
                process.Attach()
                Exit Sub
            End If
        Next
        MsgBox("No ASP.NET Development Server found")
    End Sub

End Module

• Configure Keyboard shortcut using Tools || Options as following: