diff --git a/infection_monkey/config.py b/infection_monkey/config.py
index e62820816..633534b84 100644
--- a/infection_monkey/config.py
+++ b/infection_monkey/config.py
@@ -116,6 +116,8 @@ class Configuration(object):
     dropper_date_reference_path_windows = r"%windir%\system32\kernel32.dll"
     dropper_date_reference_path_linux = '/bin/sh'
     dropper_target_path = r"C:\Windows\monkey.exe"
+    # TODO: move and rename
+    dropper_upgrade_win_64_temp_path = r"C:\Windows\monkey64.exe"
     dropper_target_path_linux = '/tmp/monkey'
 
     ###########################
diff --git a/infection_monkey/example.conf b/infection_monkey/example.conf
index 6f70f888a..3ebe3f122 100644
--- a/infection_monkey/example.conf
+++ b/infection_monkey/example.conf
@@ -23,6 +23,7 @@
     "dropper_log_path_linux": "/tmp/user-1562",
     "dropper_set_date": true,
     "dropper_target_path": "C:\\Windows\\monkey.exe",
+    "dropper_upgrade_win_64_temp_path": "C:\\Windows\\monkey64.exe",
     "dropper_target_path_linux": "/tmp/monkey",
 
 
diff --git a/infection_monkey/monkey.py b/infection_monkey/monkey.py
index 22be2cf46..b05d94fd4 100644
--- a/infection_monkey/monkey.py
+++ b/infection_monkey/monkey.py
@@ -13,6 +13,7 @@ from network.firewall import app as firewall
 from network.network_scanner import NetworkScanner
 from system_info import SystemInfoCollector
 from system_singleton import SystemSingleton
+from windows_upgrader import WindowsUpgrader
 
 __author__ = 'itamar'
 
@@ -34,6 +35,7 @@ class InfectionMonkey(object):
         self._fingerprint = None
         self._default_server = None
         self._depth = 0
+        self._opts = None
 
     def initialize(self):
         LOG.info("Monkey is initializing...")
@@ -46,13 +48,13 @@ class InfectionMonkey(object):
         arg_parser.add_argument('-t', '--tunnel')
         arg_parser.add_argument('-s', '--server')
         arg_parser.add_argument('-d', '--depth')
-        opts, self._args = arg_parser.parse_known_args(self._args)
+        self._opts, self._args = arg_parser.parse_known_args(self._args)
 
-        self._parent = opts.parent
-        self._default_tunnel = opts.tunnel
-        self._default_server = opts.server
-        if opts.depth:
-            WormConfiguration.depth = int(opts.depth)
+        self._parent = self._opts.parent
+        self._default_tunnel = self._opts.tunnel
+        self._default_server = self._opts.server
+        if self._opts.depth:
+            WormConfiguration.depth = int(self._opts.depth)
             WormConfiguration._depth_from_commandline = True
         self._keep_running = True
         self._network = NetworkScanner()
@@ -66,6 +68,10 @@ class InfectionMonkey(object):
                 LOG.debug("Default server: %s is already in command servers list" % self._default_server)
 
     def start(self):
+        if WindowsUpgrader.should_upgrade():
+            WindowsUpgrader.upgrade(self._opts)
+            return
+
         LOG.info("Monkey is running...")
 
         if firewall.is_enabled():
@@ -226,9 +232,11 @@ class InfectionMonkey(object):
 
         firewall.close()
 
-        self._singleton.unlock()
+        if not WindowsUpgrader.should_upgrade():
+            self._singleton.unlock()
 
-        if WormConfiguration.self_delete_in_cleanup and -1 == sys.executable.find('python'):
+        if WormConfiguration.self_delete_in_cleanup \
+                and -1 == sys.executable.find('python') and not WindowsUpgrader.should_upgrade():
             try:
                 if "win32" == sys.platform:
                     from _subprocess import SW_HIDE, STARTF_USESHOWWINDOW, CREATE_NEW_CONSOLE
diff --git a/infection_monkey/windows_upgrader.py b/infection_monkey/windows_upgrader.py
new file mode 100644
index 000000000..1c6049cfd
--- /dev/null
+++ b/infection_monkey/windows_upgrader.py
@@ -0,0 +1,53 @@
+import os
+import struct
+import sys
+
+import monkeyfs
+from config import WormConfiguration
+from control import ControlClient
+from exploit.tools import build_monkey_commandline_explicitly
+from model import DROPPER_CMDLINE_WINDOWS
+
+__author__ = 'itay.mizeretz'
+
+if "win32" == sys.platform:
+    from win32process import DETACHED_PROCESS
+else:
+    DETACHED_PROCESS = 0
+
+
+class WindowsUpgrader(object):
+    @staticmethod
+    def is_64bit_os():
+        return os.environ.has_key('PROGRAMFILES(X86)')
+
+    @staticmethod
+    def is_64bit_python():
+        return struct.calcsize("P") == 8
+
+    @staticmethod
+    def is_windows_os():
+        return sys.platform.startswith("win")
+
+    @staticmethod
+    def should_upgrade():
+        return WindowsUpgrader.is_windows_os() and WindowsUpgrader.is_64bit_os() \
+               and not WindowsUpgrader.is_64bit_python()
+
+    @staticmethod
+    def upgrade(opts):
+        monkey_64_path = ControlClient.download_monkey_exe_by_os(True, False)
+        with monkeyfs.open(monkey_64_path, "rb") as downloaded_monkey_file:
+            monkey_bin = downloaded_monkey_file.read()
+        with open(WormConfiguration.dropper_upgrade_win_64_temp_path, 'wb') as written_monkey_file:
+            written_monkey_file.write(monkey_bin)
+
+        monkey_options = build_monkey_commandline_explicitly(
+            opts.parent, opts.tunnel, opts.server, int(opts.depth))
+
+        monkey_cmdline = DROPPER_CMDLINE_WINDOWS % {
+            'monkey_path': WormConfiguration.dropper_target_path} + monkey_options
+        monkey_process = os.subprocess.Popen(monkey_cmdline, shell=True,
+                                             stdin=None, stdout=None, stderr=None,
+                                             close_fds=True, creationflags=DETACHED_PROCESS)
+
diff --git a/monkey_island/cc/services/config.py b/monkey_island/cc/services/config.py
index f9a7d80d2..f558eb8dc 100644
--- a/monkey_island/cc/services/config.py
+++ b/monkey_island/cc/services/config.py
@@ -446,6 +446,13 @@ SCHEMA = {
                             "default": "C:\\Windows\\monkey.exe",
                             "description": "Determines where should the dropper place the monkey on a Windows machine"
                         },
+                        "dropper_upgrade_win_64_temp_path": {
+                            "title": "Temporary upgrade path for 64bit monkey on Windows",
+                            "type": "string",
+                            "default": "C:\\Windows\\monkey64.exe",
+                            "description": "Determines where should the dropper place the 64 bit monkey while"
+                                           " upgrading on a Windows machine"
+                        },
                         "dropper_try_move_first": {
                             "title": "Try to move first",
                             "type": "boolean",