If you use Visual C++ 1.0, run the TRACER application from your Microsoft Visual C++ program group (its icon has the title "MFC Trace Options"). Select "Enable Tracing," then choose OK.
If you use Microsoft C/C++ 7.0, you must copy the AFX.INI file from the Microsoft Foundation Class Library source directory (by default, C:\C700\MFC\SRC) to your Windows directory (by default, C:\WINDOWS). This file should contain a section such as the following:
As long as TraceEnabled is set to 1, tracing is enabled.
This AFX.INI file is the same for both C/C++ 7.0 and Visual C++ 1.0. In MSVC 2.x, the TRACE output automatically goes to the 'Debug' window when you run in the debugger.
VC+ Knowledge Base, 6/7/95