This code gets Win32 error text. It is written to be read and understood on the first pass. Its arbitrary use of a static buffer is simply to not force one to remember to free the text it returns. It does sacrifice thread safety. It is also written to be a candidate for wrapping in __try/__except as well as try/catch exception handing. The use of objects such as CString would inhibit __try/__except vis-a-vis stack unwinding. Hopefully it's hard to break and easy to change.

#include <windows.h>
#include <tchar.h>
#include <stdio.h>
#include <conio.h>

// In Visual Studio, in Project > Properties > General > Character Set: use 'Not Set' or 'Multi-Byte'
char *GetErrorText(DWORD dwCode)
{
    static char buff[2000]        // Longest is 403 bytes, but memory is cheap.
    memset(buff,0,sizeof(buff));
    char *pmsg;
    SetLastError(0);
    int nbytes = FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER | 
            FORMAT_MESSAGE_FROM_SYSTEM,		// formatting options flag
            NULL,                		// not a source DLL or format string
            dwCode,                		// returned by GetLastError()
            MAKELANGID(LANG_NEUTRAL,SUBLANG_DEFAULT),
            (LPTSTR)&pmsg,       	     	// var to recv alloc'd buffer address

            sizeof(buff)-2,NULL);
    DWORD dw = GetLastError();
    if (dw==0)	// NO_ERROR, originally defined as ERROR_SUCCESS
    {        	// usually ERROR_INVALID_PARAMETER (87L) ' The parameter is incorrect.'
        strcpy_s(buff,pmsg);    
        LocalFree((HLOCAL)pmsg); // Free pmsg after copying to buff[]  
    }
    return buff;
}
int main()
{
    for (int code=0; code<2000000; code++)
    {
        - 
        if (strlen(msg))
        {
            printf("Win32 Code %3d: %s", code, msg);  // Already has <CR><LF> on end
//            Sleep(20);    // uncomment to see it scroll past
        }
    }
    // Will keep the console up until you press a key.
    puts("\nPress any key to continue....");
    while (!_kbhit()) Sleep(10);    
}

Get Windows Win32 Error Text - Simplified