diff --git a/README.md b/README.md
index ba670b7..8e5a9e0 100644
--- a/README.md
+++ b/README.md
@@ -3,7 +3,7 @@ c4 - C in four functions
 
 An exercise in minimalism.
 
-Try the following:
+Try the following under GNU/Linux:
 
     gcc -o c4 c4.c  (you may need the -m32 option on 64bit machines)
     ./c4 hello.c
@@ -12,3 +12,13 @@ Try the following:
     ./c4 c4.c hello.c
     ./c4 c4.c c4.c hello.c
 
+
+Try the following under Microsoft Windows/Visual Studio 2017 in the "x86 Native Tools Command Prompt for VS 2017" or "x64_x86 Cross Tools Command Prompt for VS 2017":
+
+    cl c4.c
+    c4 hello.c
+    c4 -s hello.c
+    
+    c4 c4.c hello.c
+    c4 c4.c c4.c hello.c
+
diff --git a/c4.c b/c4.c
index 29e35b1..7c4f406 100644
--- a/c4.c
+++ b/c4.c
@@ -9,7 +9,9 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <memory.h>
+#ifndef _WIN32
 #include <unistd.h>
+#endif
 #include <fcntl.h>
 
 char *p, *lp, // current position in source code