Compile error Error C2370: ' this_file ': redefinition solution

A project was previously AboutBox, and was later removed. Recently joined AboutBox, do not want to encounter the following error:
--------------------Configuration:msnlike_dll-win32 Debug--------------------
Compiling ...
MainFrm.cpp
E:/work/messangerinterface/msnlike_dll/msnlike_dll/aboutdlg.cpp: Error C2370: ' this_file ': redefinition; Different storage class
E:/work/messangerinterface/msnlike_dll/msnlike_dll/mainfrm.cpp (): See Declaration of ' This_file '
Error executing cl.exe.

MSNLIKE_DLL.DLL-1 error (s), 0 warning (s)

Careful search on the internet, found that there are few solutions, after careful investigation found that the problem is:
By mistakenly adding the following statement to the Mainfrm.cpp
#include "AboutDlg.cpp"