Index: Lib/distutils/msvc9compiler.py
===================================================================
--- Lib/distutils/msvc9compiler.py	(revision 66172)
+++ Lib/distutils/msvc9compiler.py	(working copy)
@@ -193,17 +193,6 @@
             reduced_paths.append(np)
     return reduced_paths
 
-def removeDuplicates(variable):
-    """Remove duplicate values of an environment variable.
-    """
-    oldList = variable.split(os.pathsep)
-    newList = []
-    for i in oldList:
-        if i not in newList:
-            newList.append(i)
-    newVariable = os.pathsep.join(newList)
-    return newVariable
-
 def find_vcvarsall(version):
     """Find the vcvarsall.bat file
 
@@ -266,9 +255,8 @@
         key, value = line.split('=', 1)
         key = key.lower()
         if key in interesting:
-            if value.endswith(os.pathsep):
-                value = value[:-1]
-            result[key] = removeDuplicates(value)
+            normalized = normalize_and_reduce_paths(value.split(os.pathsep))
+            result[key] = os.pathsep.join(normalized)
 
     if len(result) != len(interesting):
         raise ValueError(str(list(result.keys())))