diff --git a/builder/nutanix/config.go b/builder/nutanix/config.go
index 6134c19..77b6a63 100644
--- a/builder/nutanix/config.go
+++ b/builder/nutanix/config.go
@@ -7,6 +7,7 @@ import (
 	"fmt"
 	"log"
 	"net"
+	"strings"
 	"time"
 
 	"github.com/hashicorp/packer-plugin-sdk/bootcommand"
@@ -128,6 +129,7 @@ type VmConfig struct {
 	Core                   int64      `mapstructure:"core" json:"core" required:"false"`
 	MemoryMB               int64      `mapstructure:"memory_mb" json:"memory_mb" required:"false"`
 	UserData               string     `mapstructure:"user_data" json:"user_data" required:"false"`
+	WindowsInstallType     string     `mapstructure:"windows_install_type" json:"windows_install_type" required:"false"`
 	VMCategories           []Category `mapstructure:"vm_categories" required:"false"`
 	Project                string     `mapstructure:"project" required:"false"`
 	GPU                    []GPU      `mapstructure:"gpu" required:"false"`
@@ -319,6 +321,14 @@ func (c *Config) Prepare(raws ...interface{}) ([]string, error) {
 		errs = packersdk.MultiErrorAppend(errs, fmt.Errorf("missing nutanix_password"))
 	}
 
+	switch strings.ToUpper(c.VmConfig.WindowsInstallType) {
+	case "", "PREPARED", "FRESH":
+		// ok
+	default:
+		errs = packersdk.MultiErrorAppend(errs,
+			fmt.Errorf("windows_install_type must be FRESH or PREPARED, got %q", c.VmConfig.WindowsInstallType))
+	}
+
 	if c.VmConfig.VMName == "" {
 		p := fmt.Sprintf("Packer-%s", random.String(random.PossibleAlphaNumUpper, 8))
 		log.Println("No vmname assigned, setting to " + p)
diff --git a/builder/nutanix/config.hcl2spec.go b/builder/nutanix/config.hcl2spec.go
index 6478af3..5170caf 100644
--- a/builder/nutanix/config.hcl2spec.go
+++ b/builder/nutanix/config.hcl2spec.go
@@ -159,6 +159,7 @@ type FlatConfig struct {
 	Core                      *int64              `mapstructure:"core" json:"core" required:"false" cty:"core" hcl:"core"`
 	MemoryMB                  *int64              `mapstructure:"memory_mb" json:"memory_mb" required:"false" cty:"memory_mb" hcl:"memory_mb"`
 	UserData                  *string             `mapstructure:"user_data" json:"user_data" required:"false" cty:"user_data" hcl:"user_data"`
+	WindowsInstallType        *string             `mapstructure:"windows_install_type" json:"windows_install_type" required:"false" cty:"windows_install_type" hcl:"windows_install_type"`
 	VMCategories              []FlatCategory      `mapstructure:"vm_categories" required:"false" cty:"vm_categories" hcl:"vm_categories"`
 	Project                   *string             `mapstructure:"project" required:"false" cty:"project" hcl:"project"`
 	GPU                       []FlatGPU           `mapstructure:"gpu" required:"false" cty:"gpu" hcl:"gpu"`
@@ -282,6 +283,7 @@ func (*FlatConfig) HCL2Spec() map[string]hcldec.Spec {
 		"core":                         &hcldec.AttrSpec{Name: "core", Type: cty.Number, Required: false},
 		"memory_mb":                    &hcldec.AttrSpec{Name: "memory_mb", Type: cty.Number, Required: false},
 		"user_data":                    &hcldec.AttrSpec{Name: "user_data", Type: cty.String, Required: false},
+		"windows_install_type":         &hcldec.AttrSpec{Name: "windows_install_type", Type: cty.String, Required: false},
 		"vm_categories":                &hcldec.BlockListSpec{TypeName: "vm_categories", Nested: hcldec.ObjectSpec((*FlatCategory)(nil).HCL2Spec())},
 		"project":                      &hcldec.AttrSpec{Name: "project", Type: cty.String, Required: false},
 		"gpu":                          &hcldec.BlockListSpec{TypeName: "gpu", Nested: hcldec.ObjectSpec((*FlatGPU)(nil).HCL2Spec())},
@@ -447,6 +449,7 @@ type FlatVmConfig struct {
 	Core                   *int64         `mapstructure:"core" json:"core" required:"false" cty:"core" hcl:"core"`
 	MemoryMB               *int64         `mapstructure:"memory_mb" json:"memory_mb" required:"false" cty:"memory_mb" hcl:"memory_mb"`
 	UserData               *string        `mapstructure:"user_data" json:"user_data" required:"false" cty:"user_data" hcl:"user_data"`
+	WindowsInstallType     *string        `mapstructure:"windows_install_type" json:"windows_install_type" required:"false" cty:"windows_install_type" hcl:"windows_install_type"`
 	VMCategories           []FlatCategory `mapstructure:"vm_categories" required:"false" cty:"vm_categories" hcl:"vm_categories"`
 	Project                *string        `mapstructure:"project" required:"false" cty:"project" hcl:"project"`
 	GPU                    []FlatGPU      `mapstructure:"gpu" required:"false" cty:"gpu" hcl:"gpu"`
@@ -481,6 +484,7 @@ func (*FlatVmConfig) HCL2Spec() map[string]hcldec.Spec {
 		"core":                    &hcldec.AttrSpec{Name: "core", Type: cty.Number, Required: false},
 		"memory_mb":               &hcldec.AttrSpec{Name: "memory_mb", Type: cty.Number, Required: false},
 		"user_data":               &hcldec.AttrSpec{Name: "user_data", Type: cty.String, Required: false},
+		"windows_install_type":    &hcldec.AttrSpec{Name: "windows_install_type", Type: cty.String, Required: false},
 		"vm_categories":           &hcldec.BlockListSpec{TypeName: "vm_categories", Nested: hcldec.ObjectSpec((*FlatCategory)(nil).HCL2Spec())},
 		"project":                 &hcldec.AttrSpec{Name: "project", Type: cty.String, Required: false},
 		"gpu":                     &hcldec.BlockListSpec{TypeName: "gpu", Nested: hcldec.ObjectSpec((*FlatGPU)(nil).HCL2Spec())},
diff --git a/builder/nutanix/config_test.go b/builder/nutanix/config_test.go
new file mode 100644
index 0000000..843591d
--- /dev/null
+++ b/builder/nutanix/config_test.go
@@ -0,0 +1,53 @@
+package nutanix
+
+import (
+	"strings"
+	"testing"
+)
+
+func minimalValidConfig(extra map[string]interface{}) map[string]interface{} {
+	cfg := map[string]interface{}{
+		"nutanix_endpoint": "pc.example.com",
+		"nutanix_username": "admin",
+		"nutanix_password": "password",
+		"cluster_name":     "cluster-1",
+		"os_type":          "Linux",
+		"communicator":     "none",
+		"vm_disks": []map[string]interface{}{
+			{
+				"image_type":        "DISK_IMAGE",
+				"source_image_name": "img",
+				"disk_size_gb":      40,
+			},
+		},
+	}
+	for k, v := range extra {
+		cfg[k] = v
+	}
+	return cfg
+}
+
+func TestPrepareRejectsInvalidWindowsInstallType(t *testing.T) {
+	c := &Config{}
+	_, err := c.Prepare(minimalValidConfig(map[string]interface{}{
+		"nutanix_username":     "admin",
+		"nutanix_password":     "password",
+		"windows_install_type": "fresh",
+	}))
+	if err != nil {
+		t.Fatalf("expected case-insensitive match to succeed, got: %v", err)
+	}
+
+	c2 := &Config{}
+	_, err = c2.Prepare(minimalValidConfig(map[string]interface{}{
+		"nutanix_username":     "admin",
+		"nutanix_password":     "password",
+		"windows_install_type": "INVALID",
+	}))
+	if err == nil {
+		t.Fatal("expected Prepare to fail with invalid windows_install_type")
+	}
+	if !strings.Contains(err.Error(), "windows_install_type must be FRESH or PREPARED") {
+		t.Errorf("unexpected error: %v", err)
+	}
+}
diff --git a/builder/nutanix/driver.go b/builder/nutanix/driver.go
index 1c8f409..e442f1c 100644
--- a/builder/nutanix/driver.go
+++ b/builder/nutanix/driver.go
@@ -755,6 +755,12 @@ func (d *NutanixDriver) CreateRequest(ctx context.Context, vmConfig VmConfig, st
 			log.Printf("CloudInit configured for Linux VM")
 		} else if vmConfig.OSType == "Windows" {
 			sysprep := vmmModels.NewSysprep()
+			if strings.EqualFold(vmConfig.WindowsInstallType, "FRESH") {
+				sysprep.InstallType = vmmModels.INSTALLTYPE_FRESH.Ref()
+			} else {
+				sysprep.InstallType = vmmModels.INSTALLTYPE_PREPARED.Ref()
+			}
+			log.Printf("Windows Sysprep InstallType: %s", sysprep.InstallType.GetName())
 			unattendXml := vmmModels.NewUnattendxml()
 			unattendXml.Value = &vmConfig.UserData
 			sysprep.SysprepScript = vmmModels.NewOneOfSysprepSysprepScript()
diff --git a/builder/nutanix/step_shutdown_vm.go b/builder/nutanix/step_shutdown_vm.go
index 5cab987..5b610b0 100644
--- a/builder/nutanix/step_shutdown_vm.go
+++ b/builder/nutanix/step_shutdown_vm.go
@@ -53,19 +53,23 @@ func (s *StepShutdown) Run(ctx context.Context, state multistep.StateBag) multis
 			log.Printf("executing shutdown command: %s", s.Command)
 			cmd := &packersdk.RemoteCmd{Command: s.Command}
 			if err := cmd.RunWithUi(ctx, comm, ui); err != nil {
-				err := fmt.Errorf("failed to send shutdown command: %s", err)
-				state.Put("error", err)
-				ui.Error(err.Error())
-				return multistep.ActionHalt
+				// Communicator errors during shutdown are expected — the
+				// shutdown command (e.g. sysprep /shutdown) may power off
+				// the VM before the communicator can read the exit status.
+				// Log a warning and fall through to the power-state polling
+				// loop, which will detect the VM is off.
+				log.Printf("shutdown command returned error (expected if VM is shutting down): %s", err)
+				ui.Say("Shutdown command disconnected (expected during sysprep/shutdown). Waiting for VM to power off...")
 			}
 
 		} else {
 			ui.Say("Halting the virtual machine...")
 			if err := driver.PowerOff(ctx, vmUUID); err != nil {
-				err := fmt.Errorf("error stopping VM: %s", err)
-				state.Put("error", err)
-				ui.Error(err.Error())
-				return multistep.ActionHalt
+				// PowerOff may fail if the VM is already off (e.g. sysprep
+				// /shutdown ran as the last provisioner). Log a warning and
+				// fall through to the polling loop.
+				log.Printf("PowerOff returned error (may be expected if VM already shut down): %s", err)
+				ui.Say("PowerOff returned error — checking if VM is already off...")
 			}
 		}
 	} else {