diff --git a/gns3server/handlers/api/qemu_handler.py b/gns3server/handlers/api/qemu_handler.py
index 9a8cff10..6d09f5b4 100644
--- a/gns3server/handlers/api/qemu_handler.py
+++ b/gns3server/handlers/api/qemu_handler.py
@@ -152,7 +152,7 @@ class QEMUHandler:
                 and "-no-kvm" not in vm.options:
             pm = ProjectManager.instance()
             if pm.check_hardware_virtualization(vm) is False:
-                raise HTTPConflict(text="Cannot start VM with KVM enabled because hardware virtualization is already used by another software like VMware or VirtualBox")
+                raise HTTPConflict(text="Cannot start VM with KVM enabled because hardware virtualization (VT-x/AMD-V) is already used by another software like VMware or VirtualBox")
         yield from vm.start()
         response.set_status(204)
 
diff --git a/gns3server/handlers/api/virtualbox_handler.py b/gns3server/handlers/api/virtualbox_handler.py
index a66e472d..c5c4e244 100644
--- a/gns3server/handlers/api/virtualbox_handler.py
+++ b/gns3server/handlers/api/virtualbox_handler.py
@@ -192,10 +192,10 @@ class VirtualBoxHandler:
 
         vbox_manager = VirtualBox.instance()
         vm = vbox_manager.get_vm(request.match_info["vm_id"], project_id=request.match_info["project_id"])
-        if sys.platform.startswith("linux") and (yield from vm.check_hw_virtualization()):
+        if (yield from vm.check_hw_virtualization()):
             pm = ProjectManager.instance()
             if pm.check_hardware_virtualization(vm) is False:
-                raise HTTPConflict(text="Cannot start VM because KVM is being used by a Qemu VM")
+                raise HTTPConflict(text="Cannot start VM because hardware virtualization (VT-x/AMD-V) is already used by another software like VMware or KVM (on Linux)")
         yield from vm.start()
         response.set_status(204)
 
diff --git a/gns3server/handlers/api/vmware_handler.py b/gns3server/handlers/api/vmware_handler.py
index c62a0c1f..295ae6fe 100644
--- a/gns3server/handlers/api/vmware_handler.py
+++ b/gns3server/handlers/api/vmware_handler.py
@@ -160,6 +160,10 @@ class VMwareHandler:
 
         vmware_manager = VMware.instance()
         vm = vmware_manager.get_vm(request.match_info["vm_id"], project_id=request.match_info["project_id"])
+        if vm.check_hw_virtualization():
+            pm = ProjectManager.instance()
+            if pm.check_hardware_virtualization(vm) is False:
+                raise HTTPConflict(text="Cannot start VM because hardware virtualization (VT-x/AMD-V) is already used by another software like VirtualBox or KVM (on Linux)")
         yield from vm.start()
         response.set_status(204)
 
diff --git a/gns3server/modules/project_manager.py b/gns3server/modules/project_manager.py
index 6d30bc99..7ecf4e54 100644
--- a/gns3server/modules/project_manager.py
+++ b/gns3server/modules/project_manager.py
@@ -103,19 +103,10 @@ class ProjectManager:
         :returns: boolean
         """
 
-        from .qemu import QemuVM
-        from .virtualbox import VirtualBoxVM
-        from .vmware import VMwareVM
         for project in self._projects.values():
             for vm in project.vms:
                 if vm == source_vm:
                     continue
-                if vm.hw_virtualization:
-                    if isinstance(source_vm, QemuVM) and not isinstance(vm, QemuVM):
-                        # A Qemu VM won't start if any other virtualization software uses hardware virtualization
-                        return False
-                    elif isinstance(source_vm, VirtualBoxVM) and not isinstance(vm, VirtualBoxVM) and not isinstance(vm, VMwareVM):
-                        # A VirtualBox VM won't start if KVM is being used
-                        return False
-                    # VMware doesn't seem to be bothered by any other virtualization software.
+                if vm.hw_virtualization and vm.__class__.__name__ != source_vm.__class__.__name__:
+                    return False
         return True
diff --git a/gns3server/modules/vmware/vmware_vm.py b/gns3server/modules/vmware/vmware_vm.py
index 4becdc86..193fc803 100644
--- a/gns3server/modules/vmware/vmware_vm.py
+++ b/gns3server/modules/vmware/vmware_vm.py
@@ -344,6 +344,22 @@ class VMwareVM(BaseVM):
         if parse_version(self._ubridge_hypervisor.version) < parse_version('0.9.1'):
             raise VMwareError("uBridge version must be >= 0.9.1, detected version is {}".format(self._ubridge_hypervisor.version))
 
+    def check_hw_virtualization(self):
+        """
+        Returns either hardware virtualization is activated or not.
+
+        :returns: boolean
+        """
+
+        try:
+            self._vmx_pairs = self.manager.parse_vmware_file(self._vmx_path)
+        except OSError as e:
+            raise VMwareError('Could not read VMware VMX file "{}": {}'.format(self._vmx_path, e))
+
+        if self._get_vmx_setting("vhv.enable", "TRUE"):
+            return True
+        return False
+
     @asyncio.coroutine
     def start(self):
         """