diff --git a/ares/buildconf.bat b/ares/buildconf.bat
index 3cd901098..4b6a6e213 100644
--- a/ares/buildconf.bat
+++ b/ares/buildconf.bat
@@ -1,8 +1,21 @@
 @echo off
-REM set up a CVS tree to build when there's no autotools
-REM $Revision$
-REM $Date$
+REM
+REM $Id$
+REM
+REM This batch file must be used to set up a CVS tree to build on
+REM systems where there is no autotools support (i.e. Microsoft).
+REM
+REM This file is not included nor needed for c-ares' release
+REM archives, neither for c-ares' daily snapshot archives.
 
-REM create ares_build.h
+if exist CVS-INFO goto start_doing
+ECHO ERROR: This file shall only be used with a c-ares CVS tree checkout.
+goto end_all
+:start_doing
+
+if not exist ares_build.h.dist goto end_ares_build_h
 copy /Y ares_build.h.dist ares_build.h
+:end_ares_build_h
+
+:end_all
 
diff --git a/buildconf.bat b/buildconf.bat
index 82e5c26fd..10d3c59e6 100644
--- a/buildconf.bat
+++ b/buildconf.bat
@@ -1,16 +1,32 @@
 @echo off
-REM set up a CVS tree to build when there's no autotools
-REM $Revision$
-REM $Date$
+REM
+REM $Id$
+REM
+REM This batch file must be used to set up a CVS tree to build on
+REM systems where there is no autotools support (i.e. Microsoft).
+REM
+REM This file is not included nor needed for curl's release
+REM archives, neither for curl's daily snapshot archives.
+
+if exist CVS-INFO goto start_doing
+ECHO ERROR: This file shall only be used with a curl CVS tree checkout.
+goto end_all
+:start_doing
 
 REM create hugehelp.c
-copy src\hugehelp.c.cvs src\hugehelp.c
+if not exist src\hugehelp.c.cvs goto end_hugehelp_c
+copy /Y src\hugehelp.c.cvs src\hugehelp.c
+:end_hugehelp_c
 
 REM create Makefile
-copy Makefile.dist Makefile
+if not exist Makefile.dist goto end_makefile
+copy /Y Makefile.dist Makefile
+:end_makefile
 
 REM create curlbuild.h
-copy include\curl\curlbuild.h.dist include\curl\curlbuild.h
+if not exist include\curl\curlbuild.h.dist goto end_curlbuild_h
+copy /Y include\curl\curlbuild.h.dist include\curl\curlbuild.h
+:end_curlbuild_h
 
 REM setup c-ares CVS tree
 if not exist ares\buildconf.bat goto end_c_ares
@@ -19,3 +35,5 @@ call buildconf.bat
 cd ..
 :end_c_ares
 
+:end_all
+