Index: dll/win32/shimgvw/shimgvw.c
===================================================================
--- dll/win32/shimgvw/shimgvw.c	(revision 60916)
+++ dll/win32/shimgvw/shimgvw.c	(working copy)
@@ -70,6 +70,13 @@
 }
 
 static VOID
+ImageView_UpdateWindow(HWND hwnd)
+{
+    InvalidateRect(hwnd, NULL, FALSE);
+    UpdateWindow(hwnd);
+}
+
+static VOID
 ImageView_DrawImage(HWND hwnd)
 {
     GpGraphics *graphics;
@@ -338,9 +345,17 @@
 
                 break;
                 case IDC_ROT1:
+                {
+                    GdipImageRotateFlip(image, Rotate270FlipNone);
+                    ImageView_UpdateWindow(hwnd);
+                }
 
                 break;
                 case IDC_ROT2:
+                {
+                    GdipImageRotateFlip(image, Rotate90FlipNone);
+                    ImageView_UpdateWindow(hwnd);
+                }
 
                 break;
             }