To set a breakpoint on a Windows API function with NT symbols loaded:
In the function breakpoint, enter the function name together with the name of the DLL where the function resides (see the context operator). In 32-bit code, use the decorated form of the function name. To set a breakpoint on MessageBeep, for example, you must enter the following.
{,,USER32.DLL}_MessageBeep@4
To obtain the decorated name, see Viewing Decorated Names.
You can test the decorated name and view it in disassembly code. While paused at the function in the Visual Studio debugger, right-click the function in the code editor or call stack window and choose Go to Disassembly.
In 64-bit code, you can use the undecorated name.
{,,USER32.DLL}MessageBeep