diff --git a/README.rst b/README.rst
index 11f9f10..942e4cb 100644
--- a/README.rst
+++ b/README.rst
@@ -169,6 +169,10 @@ Options
     *Note*: Currently only the overviewer.dat file is deleted when you run with
     this option
 
+--forcerender
+    Force re-rendering the entire map (or the given regionlist). This
+    is an easier way to completely re-render without deleting the map.
+
 --regionlist=regionlist
     Use this option to specify manually a list of regions to consider for
     updating. Without this option, every chunk in every region is checked for
diff --git a/overviewer.py b/overviewer.py
index 6dfbd68..74c5414 100755
--- a/overviewer.py
+++ b/overviewer.py
@@ -39,6 +39,15 @@ this_dir = util.get_program_path()
 try:
     import c_overviewer
 except ImportError:
+    ## if this is a frozen windows package, the following error messages about
+    ## building the c_overviewer extension are not appropriate
+    if hasattr(sys, "frozen"):
+        print "Something has gone wrong importing the c_overviewer extension.  Please"
+        print "make sure the 2008 and 2010 redistributable packages from Microsoft"
+        print "are installed."
+        sys.exit(1)
+
+
     ## try to find the build extension
     ext = os.path.join(this_dir, "c_overviewer.%s" % ("pyd" if platform.system() == "Windows" else "so"))
     if os.path.exists(ext):