VS.Net broke my project

Tech-Archive recommends: Fix windows errors by optimizing your registry

From: Developer (wanderer_at_mapinfo.nope.com)
Date: 09/29/04 

Date: Wed, 29 Sep 2004 12:28:12 -0400

Hello,

20 minutes ago I was building and running my VS.Net 2003 C# project.
Now when I try to build, I get this message:
    Could not find 'MyCompany.NewProduct.Windows.Forms.AppMain' specified
for Main method

What the heck happened?

This code is in a file that is in the project:

namespace MyCompany.NewProduct.Windows.Forms
{
/// <summary>
/// Summary description for AppMain.
/// </summary>
public class AppMain : System.Windows.Forms.Form
{
  private MenuItem noWindowsMenuItem;
  // etc.
}

TIA for any help in fixing this, and any suggestions for how to prevent
VS.Net from breaking my projects...

CB