INSTALL: remove MinGW

INSTALL

@@ -25,21 +25,20 @@ Currently, mosh supports following O/Ses.
 - Linux 2.6 (Debian, Ubuntu, Fedora, ...)
   see doc/README.Linux
 
+- MacOS X (10.5 "Leopard" or later)
+  see doc/README.MacOSX (or doc/README.CMake for XCode build)
+
+- Windows XP or later(32bit): Visual Studio
+  see doc/README.CMake
+
 - FreeBSD 8.x or CURRENT
   see doc/README.FreeBSD
 
-- MacOS X (10.5 "Leopard" or later)
-  see doc/README.MacOSX (or doc/README.CMake for XCode build)
+- NetBSD 5.x
+  see doc/README.NetBSD
 
 - Cygwin 1.7.x
   see doc/README.Cygwin
 
-- Windows XP or later(32bit): MinGW
-  see doc/README.MinGW and doc/README.CMake
-- Windows XP or later(32bit): Visual Studio
-  see doc/README.CMake
-- Windows 7(64bit): Visual Studio
-  (We don't recommend Win64 build for now ... Try Win32 builds.)
-
 - MonaOS