diff --git a/gns3server/modules/attic.py b/gns3server/modules/attic.py
index 8c1fae63..fa31e50e 100644
--- a/gns3server/modules/attic.py
+++ b/gns3server/modules/attic.py
@@ -121,11 +121,14 @@ def has_privileged_access(executable):
     :returns: True or False
     """
 
+    if sys.platform.startswith("win"):
+        # do not check anything on Windows
+        return True
+
     if os.geteuid() == 0:
         # we are root, so we should have privileged access.
         return True
-
-    if not sys.platform.startswith("win") and os.stat(executable).st_mode & stat.S_ISVTX == stat.S_ISVTX:
+    if os.stat(executable).st_mode & stat.S_ISVTX == stat.S_ISVTX:
         # the executable has a sticky bit.
         return True
 
diff --git a/gns3server/modules/iou/iou_device.py b/gns3server/modules/iou/iou_device.py
index 6c5b8704..ece451be 100644
--- a/gns3server/modules/iou/iou_device.py
+++ b/gns3server/modules/iou/iou_device.py
@@ -806,7 +806,6 @@ class IOUDevice(object):
         -N            Ignore the NETMAP file
         """
 
-        #TODO: add support for keepalive and watchdog
         command = [self._path]
         if len(self._ethernet_adapters) != 2:
             command.extend(["-e", str(len(self._ethernet_adapters))])
diff --git a/gns3server/modules/vpcs/vpcs_device.py b/gns3server/modules/vpcs/vpcs_device.py
index 8fb674ed..9c7957a8 100644
--- a/gns3server/modules/vpcs/vpcs_device.py
+++ b/gns3server/modules/vpcs/vpcs_device.py
@@ -25,7 +25,9 @@ import sys
 import subprocess
 import signal
 import shutil
+import re
 
+from pkg_resources import parse_version
 from .vpcs_error import VPCSError
 from .adapters.ethernet_adapter import EthernetAdapter
 from .nios.nio_udp import NIO_UDP
@@ -343,6 +345,24 @@ class VPCSDevice(object):
 
         return self._started
 
+    def _check_vpcs_version(self):
+        """
+        Checks if the VPCS executable version is >= 0.5b1.
+        """
+
+        try:
+            output = subprocess.check_output([self._path, "-v"], stderr=subprocess.STDOUT, cwd=self._working_dir)
+            match = re.search("Welcome to Virtual PC Simulator, version ([0-9a-z\.]+)", output.decode("utf-8"))
+            if match:
+                version = match.group(1)
+                print(version)
+                if parse_version(version) < parse_version("0.5b1"):
+                    raise VPCSError("VPCS executable version must be >= 0.5b1")
+            else:
+                raise VPCSError("Could not determine the VPCS version for {}".format(self._path))
+        except OSError as e:
+            raise VPCSError("Error while looking for the VPCS version: {}".format(e))
+
     def start(self):
         """
         Starts the VPCS process.
@@ -359,6 +379,8 @@ class VPCSDevice(object):
             if not os.access(self._path, os.X_OK):
                 raise VPCSError("VPCS program '{}' is not executable".format(self._path))
 
+            self._check_vpcs_version()
+
             if not self._ethernet_adapter.get_nio(0):
                 raise VPCSError("This VPCS instance must be connected in order to start")