You cannot debug a managed application in Visual Studio .NET if Windows was started in debug mode

When you try to debug a managed application (one that makes use of the .NET Framework) with Visual Studio .NET software, you may receive the following error message: -or- NOTE: The second error message may have other causes and resolutions.

This problem happens if Windows was started in debug mode on the system. This stops the Visual Studio .NET debugger from debugging managed applications.

To determine whether your system was started in debug mode, see the following Microsoft Knowledge Base article:

There are two ways that you can resolve this problem. Do either of the following:

• Resolution 1
  1. Right-click the Project Name in Solution Explorer, and then click Properties.
  2. In the left pane of Properties, click to select Configuration Properties.
  3. Click to select Debugging.
  4. In the right pane, click to select the Unmanaged code debugging check box.
• Resolution 2
  1. In Microsoft Notepad, open Boot.ini, which is located in the System Drive folder (usually C:\). This file may be hidden and read-only, so you may have to use dir /ASH to find it.
  2. Remove all of the following switches, if found in the file:
     • /debug
     • /debugport
     • /baudrate
     
     
  3. Restart the computer, start Visual Studio .NET, and then debug.

For more information, click the following article number to view the article in the Microsoft Knowledge Base: