Sconscript: use WIN32_WINNT_WIN7 in architecture sconscript in order …

…to make NVDA more compatible with Windows 7 and later. re nvaccess#6718.

nvdaHelper/archBuild_sconscript

@@ -1,7 +1,7 @@
 ###
 #This file is a part of the NVDA project.
-#URL: http://www.nvda-project.org/
-#Copyright 2006-2010 NVDA contributers.
+#URL: https://www.nvaccess.org/
+#Copyright 2006-2017 NV Access Limited
 #This program is free software: you can redistribute it and/or modify
 #it under the terms of the GNU General Public License version 2.0, as published by
 #the Free Software Foundation.
@@ -34,7 +34,7 @@ release=env['release']
 signExec=env['signExec'] if env['certFile'] else None
 
 #Some defines and includes for the environment
-env.Append(CPPDEFINES=['UNICODE','_CRT_SECURE_NO_DEPRECATE',('LOGLEVEL','${nvdaHelperLogLevel}'),('_WIN32_WINNT','_WIN32_WINNT_WS03')])
+env.Append(CPPDEFINES=['UNICODE','_CRT_SECURE_NO_DEPRECATE',('LOGLEVEL','${nvdaHelperLogLevel}'),('_WIN32_WINNT','_WIN32_WINNT_WIN7')])
 env.Append(CCFLAGS=['/W3','/WX'])
 if 'analyze' in debug:
 	env.Append(CCFLAGS=['/analyze'])