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How to: Debug 64-Bit Applications 

This topic applies to:

Visual Studio Edition

Visual Basic



















With Visual Studio 2005, you can debug a 64-bit application running on the local machine or on a remote machine.

If you are debugging locally, Visual Studio 2005 runs under WOW64, the 32-bit x86 emulator that allows 32-bit Windows applications to run on 64-bit Windows. Local debugging under WOW64 is supported on x64 only.

If you are debugging remotely, Visual Studio 2005 can run under WOW64 or on a 32-bit machine. You can debug both IA64 and x64 applications, as well as 32-bit applications running under or x64 WOW mode or on 32-bit platforms.

To debug a 64-bit application running on a remote computer, you need to install the 64-bit remote debugger on the remote computer. The 64-bit remote debugger is available on the last disc of your Visual Studio 2005 installation set.

If you debug a 64-bit application on the local machine, Visual Studio 2005 uses remote debugging to connect between WOW64 and the 64-bit application on the same machine. For more information, see Debugging on a 64-Bit Platform. The remote debugging components will be installed automatically when you install Visual Studio 2005 on the machine.

In either case, installing remote debugging on a 64-bit machine installs both the 32-bit and 64-bit versions of the Remote Debugging Monitor. To debug a 64-bit application, you must use the correct version, which is Remote Debugger (x64) on the Start menu.

Debugging 64-bit code is almost identical to debugging 32-bit code. However, there are two differences:

  • Edit and Continue is not available for 64-bit debugging.

  • You cannot debug in mixed-mode, calls from native code to managed code, or vice versa, in 64-bit code.

For information about installing 64-bit remote debugging components, see How to: Set Up Remote Debugging.

To start the 64-bit Remote Debugging Monitor

  1. Click Start, point to All Programs, point to Microsoft Visual Studio 2005, point to Visual Studio Tools, and then click Remote Debugger (x64) or Remote Debugger (IA64)..


    From the Windows Command Prompt, run Install path\Microsoft Visual Studio 8\Common7\IDE\Remote Debugger\x64 or Install path\Microsoft Visual Studio 8\Common7\IDE\Remote Debugger\ia64.

  2. Configure the Remote Debugging Monitor for remote debugging.

See Also