diff --git a/ez_setup.py b/ez_setup.py
index 4118de3b69..9dc2c8729b 100644
--- a/ez_setup.py
+++ b/ez_setup.py
@@ -29,7 +29,7 @@
 except ImportError:
     USER_SITE = None
 
-DEFAULT_VERSION = "1.1.5"
+DEFAULT_VERSION = "1.4.2"
 DEFAULT_URL = "https://pypi.python.org/packages/source/s/setuptools/"
 
 def _python_cmd(*args):
@@ -151,6 +151,18 @@ def use_setuptools(version=DEFAULT_VERSION, download_base=DEFAULT_URL,
         return _do_download(version, download_base, to_dir,
                             download_delay)
 
+def _clean_check(cmd, target):
+    """
+    Run the command to download target. If the command fails, clean up before
+    re-raising the error.
+    """
+    try:
+        subprocess.check_call(cmd)
+    except subprocess.CalledProcessError:
+        if os.access(target, os.F_OK):
+            os.unlink(target)
+        raise
+
 def download_file_powershell(url, target):
     """
     Download the file at url to target using Powershell (which will validate
@@ -162,7 +174,7 @@ def download_file_powershell(url, target):
         '-Command',
         "(new-object System.Net.WebClient).DownloadFile(%(url)r, %(target)r)" % vars(),
     ]
-    subprocess.check_call(cmd)
+    _clean_check(cmd, target)
 
 def has_powershell():
     if platform.system() != 'Windows':
@@ -182,7 +194,7 @@ def has_powershell():
 
 def download_file_curl(url, target):
     cmd = ['curl', url, '--silent', '--output', target]
-    subprocess.check_call(cmd)
+    _clean_check(cmd, target)
 
 def has_curl():
     cmd = ['curl', '--version']
@@ -200,7 +212,7 @@ def has_curl():
 
 def download_file_wget(url, target):
     cmd = ['wget', url, '--quiet', '--output-document', target]
-    subprocess.check_call(cmd)
+    _clean_check(cmd, target)
 
 def has_wget():
     cmd = ['wget', '--version']
diff --git a/setup.py b/setup.py
index 9d91fcf3c3..1043259d3b 100755
--- a/setup.py
+++ b/setup.py
@@ -19,11 +19,11 @@
 # Don't force people to install setuptools unless
 # we have to.
 try:
-    from setuptools import setup, Feature
+    from setuptools import setup
 except ImportError:
     from ez_setup import use_setuptools
     use_setuptools()
-    from setuptools import setup, Feature
+    from setuptools import setup
 
 from distutils.cmd import Command
 from distutils.command.build_ext import build_ext
@@ -206,21 +206,21 @@ def build_extension(self, ext):
                                                   "to take advantage of the "
                                                   "extension."))
 
-c_ext = Feature(
-    "optional C extensions",
-    standard=True,
-    ext_modules=[Extension('bson._cbson',
-                           include_dirs=['bson'],
-                           sources=['bson/_cbsonmodule.c',
-                                    'bson/time64.c',
-                                    'bson/buffer.c',
-                                    'bson/encoding_helpers.c']),
-                 Extension('pymongo._cmessage',
-                           include_dirs=['bson'],
-                           sources=['pymongo/_cmessagemodule.c',
-                                    'bson/buffer.c'])])
-
-features = {}
+ext_modules = [Extension('bson._cbson',
+                         include_dirs=['bson'],
+                         sources=['bson/_cbsonmodule.c',
+                                  'bson/time64.c',
+                                  'bson/buffer.c',
+                                  'bson/encoding_helpers.c']),
+               Extension('pymongo._cmessage',
+                         include_dirs=['bson'],
+                         sources=['pymongo/_cmessagemodule.c',
+                                  'bson/buffer.c'])]
+
+extra_opts = {
+    "packages": ["bson", "pymongo", "gridfs"],
+    "test_suite": "nose.collector"
+}
 if "--no_ext" in sys.argv:
     sys.argv.remove("--no_ext")
 elif (sys.platform.startswith("java") or
@@ -241,12 +241,8 @@ def build_extension(self, ext):
 *****************************************************\n
 """)
 else:
-    features = {"c-ext": c_ext}
+    extra_opts['ext_modules'] = ext_modules
 
-extra_opts = {
-    "packages": ["bson", "pymongo", "gridfs"],
-    "test_suite": "nose.collector"
-}
 if PY3:
     extra_opts["use_2to3"] = True
     if should_run_tests:
@@ -283,7 +279,6 @@ def build_extension(self, ext):
     url="http://github.com/mongodb/mongo-python-driver",
     keywords=["mongo", "mongodb", "pymongo", "gridfs", "bson"],
     install_requires=[],
-    features=features,
     license="Apache License, Version 2.0",
     tests_require=["nose"],
     classifiers=[