diff --git a/builder/googlecompute/step_start_tunnel.go b/builder/googlecompute/step_start_tunnel.go
index 7536f705c..202cf1819 100644
--- a/builder/googlecompute/step_start_tunnel.go
+++ b/builder/googlecompute/step_start_tunnel.go
@@ -100,7 +100,7 @@ func (s *StepStartTunnel) createTempGcloudScript(args []string) (string, error)
 	s.IAPConf.IAPHashBang = fmt.Sprintf("#!%s\n", s.IAPConf.IAPHashBang)
 	log.Printf("[INFO] (google): Prepending inline gcloud setup script with %s",
 		s.IAPConf.IAPHashBang)
-	err = writer.WriteString(s.IAPConf.IAPHashBang)
+	_, err = writer.WriteString(s.IAPConf.IAPHashBang)
 	if err != nil {
 		return "", fmt.Errorf("Error preparing inline hashbang: %s", err)
 	}
diff --git a/builder/googlecompute/tunnel_driver.go b/builder/googlecompute/tunnel_driver.go
index 78d9be634..1a6ef0bd5 100644
--- a/builder/googlecompute/tunnel_driver.go
+++ b/builder/googlecompute/tunnel_driver.go
@@ -64,7 +64,7 @@ func (t *TunnelDriverLinux) StartTunnel(cancelCtx context.Context, tempScriptFil
 func (t *TunnelDriverLinux) StopTunnel() {
 	if t.cmd != nil && t.cmd.Process != nil {
 		log.Printf("Cleaning up the IAP tunnel...")
-		// Why not just s.cmd.Process.Kill()?  I'm glad you asked. The gcloud
+		// Why not just cmd.Process.Kill()?  I'm glad you asked. The gcloud
 		// call spawns a python subprocess that listens on the port, and you
 		// need to use the process _group_ id to kill this process and its
 		// daemon child. We create the group ID with the syscall.SysProcAttr
diff --git a/builder/googlecompute/tunnel_driver_windows.go b/builder/googlecompute/tunnel_driver_windows.go
index 9d5031ebc..73d739b5a 100644
--- a/builder/googlecompute/tunnel_driver_windows.go
+++ b/builder/googlecompute/tunnel_driver_windows.go
@@ -3,8 +3,13 @@
 package googlecompute
 
 import (
+	"bytes"
 	"context"
 	"fmt"
+	"log"
+	"os/exec"
+	"strings"
+	"time"
 )
 
 func NewTunnelDriver() TunnelDriver {
@@ -12,10 +17,54 @@ func NewTunnelDriver() TunnelDriver {
 }
 
 type TunnelDriverWindows struct {
+	cmd *exec.Cmd
 }
 
 func (t *TunnelDriverWindows) StartTunnel(cancelCtx context.Context, tempScriptFileName string) error {
-	return fmt.Errorf("Windows support for IAP tunnel not yet supported.")
+	// set stdout and stderr so we can read what's going on.
+	var stdout, stderr bytes.Buffer
+
+	cmd := exec.CommandContext(cancelCtx, tempScriptFileName)
+	cmd.Stdout = &stdout
+	cmd.Stderr = &stderr
+
+	err := cmd.Start()
+	log.Printf("Waiting 30s for tunnel to create...")
+	if err != nil {
+		err := fmt.Errorf("Error calling gcloud sdk to launch IAP tunnel: %s",
+			err)
+		return err
+	}
+	// Wait for tunnel to launch and gather response. TODO: do this without
+	// a sleep.
+	time.Sleep(30 * time.Second)
+
+	// Track stdout.
+	sout := stdout.String()
+	if sout != "" {
+		log.Printf("[start-iap-tunnel] stdout is:")
+	}
+
+	log.Printf("[start-iap-tunnel] stderr is:")
+	serr := stderr.String()
+	log.Println(serr)
+	if strings.Contains(serr, "ERROR") {
+		errIdx := strings.Index(serr, "ERROR:")
+		return fmt.Errorf("ERROR: %s", serr[errIdx+7:])
+	}
+	// Store successful command on step so we can access it to cancel it
+	// later.
+	t.cmd = cmd
+	return nil
 }
 
-func (t *TunnelDriverWindows) StopTunnel() {}
+func (t *TunnelDriverWindows) StopTunnel() {
+	if t.cmd != nil && t.cmd.Process != nil {
+		err := t.cmd.Process.Kill()
+		if err != nil {
+			log.Printf("Issue stopping IAP tunnel: %s", err)
+		}
+	} else {
+		log.Printf("Couldn't find IAP tunnel process to kill. Continuing.")
+	}
+}