@@ -51,8 +51,15 @@ func (d *Driver) Exec(c *execdriver.Command, processConfig *execdriver.ProcessCo

 	logrus.Debugln("commandLine: ", createProcessParms.CommandLine)

 	// Start the command running in the container.

-	pid, stdin, stdout, stderr, err := hcsshim.CreateProcessInComputeSystem(c.ID, pipes.Stdin != nil, true, !processConfig.Tty, createProcessParms)

+	pid, stdin, stdout, stderr, rc, err := hcsshim.CreateProcessInComputeSystem(c.ID, pipes.Stdin != nil, true, !processConfig.Tty, createProcessParms)

 	if err != nil {

+		// TODO Windows: TP4 Workaround. In Hyper-V containers, there is a limitation

+		// of one exec per container. This should be fixed post TP4. CreateProcessInComputeSystem

+		// will return a specific error which we handle here to give a good error message

+		// back to the user instead of an inactionable "An invalid argument was supplied"

+		if rc == hcsshim.Win32InvalidArgument {

+			return -1, fmt.Errorf("The limit of docker execs per Hyper-V container has been exceeded")

+		}

 		logrus.Errorf("CreateProcessInComputeSystem() failed %s", err)

 		return -1, err

 	}

@@ -263,7 +263,7 @@ func (d *Driver) Run(c *execdriver.Command, pipes *execdriver.Pipes, hooks execd

 	logrus.Debugf("CommandLine: %s", createProcessParms.CommandLine)

 	// Start the command running in the container.

-	pid, stdin, stdout, stderr, err := hcsshim.CreateProcessInComputeSystem(c.ID, pipes.Stdin != nil, true, !c.ProcessConfig.Tty, createProcessParms)

+	pid, stdin, stdout, stderr, _, err := hcsshim.CreateProcessInComputeSystem(c.ID, pipes.Stdin != nil, true, !c.ProcessConfig.Tty, createProcessParms)

 	if err != nil {

 		logrus.Errorf("CreateProcessInComputeSystem() failed %s", err)

 		return execdriver.ExitStatus{ExitCode: -1}, err