diff --git a/test/ruby/test_thread.rb b/test/ruby/test_thread.rb
index 0931de5..0ff947d 100644
--- a/test/ruby/test_thread.rb
+++ b/test/ruby/test_thread.rb
@@ -694,9 +694,13 @@ class TestThreadGroup < Test::Unit::TestCase
     Process.kill(:SIGINT, pid)
     Process.wait(pid)
     s = $?
-    assert_equal([false, true, false],
-                 [s.exited?, s.signaled?, s.stopped?],
-                 "[s.exited?, s.signaled?, s.stopped?]")
+    if /mswin|mingw/ =~ RUBY_PLATFORM
+      assert_equal(pid, s.pid)
+    else
+      assert_equal([false, true, false],
+                   [s.exited?, s.signaled?, s.stopped?],
+                   "[s.exited?, s.signaled?, s.stopped?]")
+    end
     t1 = Time.now.to_f
     assert_in_delta(t1 - t0, 1, 1)
   end
diff --git a/test/zlib/test_zlib.rb b/test/zlib/test_zlib.rb
index 4149c8a..8c2fbde 100644
--- a/test/zlib/test_zlib.rb
+++ b/test/zlib/test_zlib.rb
@@ -691,6 +691,7 @@ if defined? Zlib
       t.close
       Zlib::GzipWriter.open(t.path) {|gz| gz.print("foo") }
       f = open(t.path)
+      f.binmode
       assert_equal("foo", Zlib::GzipReader.wrap(f) {|gz| gz.read })
       assert_raise(IOError) { f.close }
     end
diff --git a/thread_win32.c b/thread_win32.c
index 873d37d..da971e7 100644
--- a/thread_win32.c
+++ b/thread_win32.c
@@ -231,7 +231,7 @@ static void ubf_handle(void *ptr);
 int
 rb_w32_wait_events_blocking(HANDLE *events, int num, DWORD timeout)
 {
-    return w32_wait_events(events, num, timeout, GET_THREAD());
+    return w32_wait_events(events, num, timeout, ruby_thread_from_native());
 }
 
 int
@@ -240,7 +240,7 @@ rb_w32_wait_events(HANDLE *events, int num, DWORD timeout)
     int ret;
 
     BLOCKING_REGION(ret = rb_w32_wait_events_blocking(events, num, timeout),
-		    ubf_handle, GET_THREAD());
+		    ubf_handle, ruby_thread_from_native());
     return ret;
 }
 
@@ -285,7 +285,7 @@ w32_create_thread(DWORD stack_size, w32_thread_start_func func, void *val)
 int
 rb_w32_sleep(unsigned long msec)
 {
-    return w32_wait_events(0, 0, msec, GET_THREAD());
+    return w32_wait_events(0, 0, msec, ruby_thread_from_native());
 }
 
 int WINAPI
@@ -294,7 +294,7 @@ rb_w32_Sleep(unsigned long msec)
     int ret;
 
     BLOCKING_REGION(ret = rb_w32_sleep(msec),
-		    ubf_handle, GET_THREAD());
+		    ubf_handle, ruby_thread_from_native());
     return ret;
 }
 
diff --git a/win32/win32.c b/win32/win32.c
index 7cb1b31..744c614 100644
--- a/win32/win32.c
+++ b/win32/win32.c
@@ -1132,7 +1132,7 @@ CreateChild(const WCHAR *cmd, const WCHAR *prog, SECURITY_ATTRIBUTES *psa,
 	aStartupInfo.hStdError = GetStdHandle(STD_ERROR_HANDLE);
     }
 
-    dwCreationFlags = (NORMAL_PRIORITY_CLASS);
+    dwCreationFlags = (CREATE_NEW_PROCESS_GROUP | NORMAL_PRIORITY_CLASS);
 
     if (lstrlenW(cmd) > 32767) {
 	child->pid = 0;		/* release the slot */
@@ -4094,7 +4094,13 @@ kill(int pid, int sig)
 
       case SIGINT:
 	RUBY_CRITICAL({
-	    if (!GenerateConsoleCtrlEvent(CTRL_C_EVENT, (DWORD)pid)) {
+	    DWORD ctrlEvent = CTRL_C_EVENT;
+	    if (pid != 0) {
+	        /* CTRL+C signal cannot be generated for process groups.
+		 * Instead, we use CTRL+BREAK signal. */
+	        ctrlEvent = CTRL_BREAK_EVENT;
+	    }
+	    if (!GenerateConsoleCtrlEvent(ctrlEvent, (DWORD)pid)) {
 		if ((err = GetLastError()) == 0)
 		    errno = EPERM;
 		else
@@ -5569,6 +5575,10 @@ rb_w32_read(int fd, void *buf, size_t size)
 	    }
 	}
     }
+    else {
+	err = GetLastError();
+	errno = map_errno(err);
+    }
 
     if (pol) {
 	CloseHandle(ol.hEvent);
@@ -5585,7 +5595,8 @@ rb_w32_read(int fd, void *buf, size_t size)
     ret += read;
     if (read >= len) {
 	buf = (char *)buf + read;
-	if (!(isconsole && len == 1 && (!islineinput || *((char *)buf - 1) == '\n')) && size > 0)
+	if (err != ERROR_OPERATION_ABORTED &&
+	    !(isconsole && len == 1 && (!islineinput || *((char *)buf - 1) == '\n')) && size > 0)
 	    goto retry;
     }
     if (read == 0)