diff --git a/provisioner/powershell/provisioner_test.go b/provisioner/powershell/provisioner_test.go
index e7e64d52e..749564d4d 100644
--- a/provisioner/powershell/provisioner_test.go
+++ b/provisioner/powershell/provisioner_test.go
@@ -79,8 +79,8 @@ func TestProvisionerPrepare_Defaults(t *testing.T) {
 		t.Error("expected elevated_password to be empty")
 	}
 
-	if p.config.ExecuteCommand != `powershell -executionpolicy bypass "& { if (Test-Path variable:global:ProgressPreference){$ProgressPreference='SilentlyContinue'};{{.Vars}}&'{{.Path}}';exit $LastExitCode }"` {
-		t.Fatalf(`Default command should be 'powershell -executionpolicy bypass "& { if (Test-Path variable:global:ProgressPreference){$ProgressPreference='SilentlyContinue'};{{.Vars}}&'{{.Path}}';exit $LastExitCode }"', but got '%s'`, p.config.ExecuteCommand)
+	if p.config.ExecuteCommand != `powershell -executionpolicy bypass "& { if (Test-Path variable:global:ProgressPreference){$ProgressPreference='SilentlyContinue'};. {{.Vars}}; &'{{.Path}}';exit $LastExitCode }"` {
+		t.Fatalf(`Default command should be 'powershell -executionpolicy bypass "& { if (Test-Path variable:global:ProgressPreference){$ProgressPreference='SilentlyContinue'};. {{.Vars}}; &'{{.Path}}';exit $LastExitCode }"', but got '%s'`, p.config.ExecuteCommand)
 	}
 
 	if p.config.ElevatedExecuteCommand != `powershell -executionpolicy bypass "& { if (Test-Path variable:global:ProgressPreference){$ProgressPreference='SilentlyContinue'};. {{.Vars}}; &'{{.Path}}'; exit $LastExitCode }"` {
@@ -403,7 +403,7 @@ func TestProvisionerProvision_Inline(t *testing.T) {
 	ui := testUi()
 	p := new(Provisioner)
 
-	// Defaults provided by Packer
+	// Defaults provided by Packer - env vars should not appear in cmd
 	p.config.PackerBuildName = "vmware"
 	p.config.PackerBuilderType = "iso"
 	comm := new(packer.MockCommunicator)
@@ -413,11 +413,14 @@ func TestProvisionerProvision_Inline(t *testing.T) {
 		t.Fatal("should not have error")
 	}
 
-	expectedCommand := `powershell -executionpolicy bypass "& { if (Test-Path variable:global:ProgressPreference){$ProgressPreference='SilentlyContinue'};$env:PACKER_BUILDER_TYPE=\"iso\"; $env:PACKER_BUILD_NAME=\"vmware\"; &'c:/Windows/Temp/inlineScript.ps1';exit $LastExitCode }"`
-	if comm.StartCmd.Command != expectedCommand {
-		t.Fatalf("Expect command to be: %s, got %s", expectedCommand, comm.StartCmd.Command)
+	cmd := comm.StartCmd.Command
+	re := regexp.MustCompile(`powershell -executionpolicy bypass "& { if \(Test-Path variable:global:ProgressPreference\){\$ProgressPreference='SilentlyContinue'};\. \${env:SYSTEMROOT}\\Temp\\packer-env-vars-[[:alnum:]]{8}-[[:alnum:]]{4}-[[:alnum:]]{4}-[[:alnum:]]{4}-[[:alnum:]]{12}\.ps1; &'c:/Windows/Temp/inlineScript.ps1';exit \$LastExitCode }"`)
+	matched := re.MatchString(cmd)
+	if !matched {
+		t.Fatalf("Got unexpected command: %s", cmd)
 	}
 
+	// User supplied env vars should not change things
 	envVars := make([]string, 2)
 	envVars[0] = "FOO=BAR"
 	envVars[1] = "BAR=BAZ"
@@ -430,9 +433,11 @@ func TestProvisionerProvision_Inline(t *testing.T) {
 		t.Fatal("should not have error")
 	}
 
-	expectedCommand = `powershell -executionpolicy bypass "& { if (Test-Path variable:global:ProgressPreference){$ProgressPreference='SilentlyContinue'};$env:BAR=\"BAZ\"; $env:FOO=\"BAR\"; $env:PACKER_BUILDER_TYPE=\"iso\"; $env:PACKER_BUILD_NAME=\"vmware\"; &'c:/Windows/Temp/inlineScript.ps1';exit $LastExitCode }"`
-	if comm.StartCmd.Command != expectedCommand {
-		t.Fatalf("Expect command to be: %s, got %s", expectedCommand, comm.StartCmd.Command)
+	cmd = comm.StartCmd.Command
+	re = regexp.MustCompile(`powershell -executionpolicy bypass "& { if \(Test-Path variable:global:ProgressPreference\){\$ProgressPreference='SilentlyContinue'};\. \${env:SYSTEMROOT}\\Temp\\packer-env-vars-[[:alnum:]]{8}-[[:alnum:]]{4}-[[:alnum:]]{4}-[[:alnum:]]{4}-[[:alnum:]]{12}\.ps1; &'c:/Windows/Temp/inlineScript.ps1';exit \$LastExitCode }"`)
+	matched = re.MatchString(cmd)
+	if !matched {
+		t.Fatalf("Got unexpected command: %s", cmd)
 	}
 }
 
@@ -455,11 +460,12 @@ func TestProvisionerProvision_Scripts(t *testing.T) {
 		t.Fatal("should not have error")
 	}
 
-	expectedCommand := `powershell -executionpolicy bypass "& { if (Test-Path variable:global:ProgressPreference){$ProgressPreference='SilentlyContinue'};$env:PACKER_BUILDER_TYPE=\"footype\"; $env:PACKER_BUILD_NAME=\"foobuild\"; &'c:/Windows/Temp/script.ps1';exit $LastExitCode }"`
-	if comm.StartCmd.Command != expectedCommand {
-		t.Fatalf("Expect command to be: %s, got %s", expectedCommand, comm.StartCmd.Command)
+	cmd := comm.StartCmd.Command
+	re := regexp.MustCompile(`powershell -executionpolicy bypass "& { if \(Test-Path variable:global:ProgressPreference\){\$ProgressPreference='SilentlyContinue'};\. \${env:SYSTEMROOT}\\Temp\\packer-env-vars-[[:alnum:]]{8}-[[:alnum:]]{4}-[[:alnum:]]{4}-[[:alnum:]]{4}-[[:alnum:]]{12}\.ps1; &'c:/Windows/Temp/script.ps1';exit \$LastExitCode }"`)
+	matched := re.MatchString(cmd)
+	if !matched {
+		t.Fatalf("Got unexpected command: %s", cmd)
 	}
-
 }
 
 func TestProvisionerProvision_ScriptsWithEnvVars(t *testing.T) {
@@ -488,9 +494,11 @@ func TestProvisionerProvision_ScriptsWithEnvVars(t *testing.T) {
 		t.Fatal("should not have error")
 	}
 
-	expectedCommand := `powershell -executionpolicy bypass "& { if (Test-Path variable:global:ProgressPreference){$ProgressPreference='SilentlyContinue'};$env:BAR=\"BAZ\"; $env:FOO=\"BAR\"; $env:PACKER_BUILDER_TYPE=\"footype\"; $env:PACKER_BUILD_NAME=\"foobuild\"; &'c:/Windows/Temp/script.ps1';exit $LastExitCode }"`
-	if comm.StartCmd.Command != expectedCommand {
-		t.Fatalf("Expect command to be: %s, got %s", expectedCommand, comm.StartCmd.Command)
+	cmd := comm.StartCmd.Command
+	re := regexp.MustCompile(`powershell -executionpolicy bypass "& { if \(Test-Path variable:global:ProgressPreference\){\$ProgressPreference='SilentlyContinue'};\. \${env:SYSTEMROOT}\\Temp\\packer-env-vars-[[:alnum:]]{8}-[[:alnum:]]{4}-[[:alnum:]]{4}-[[:alnum:]]{4}-[[:alnum:]]{12}\.ps1; &'c:/Windows/Temp/script.ps1';exit \$LastExitCode }"`)
+	matched := re.MatchString(cmd)
+	if !matched {
+		t.Fatalf("Got unexpected command: %s", cmd)
 	}
 }
 
@@ -547,11 +555,11 @@ func TestProvisioner_createFlattenedEnvVars_windows(t *testing.T) {
 		{"FOO==bar"},           // User env var with value starting with equals
 	}
 	expected := []string{
-		`$env:PACKER_BUILDER_TYPE=\"iso\"; $env:PACKER_BUILD_NAME=\"vmware\"; `,
-		`$env:FOO=\"bar\"; $env:PACKER_BUILDER_TYPE=\"iso\"; $env:PACKER_BUILD_NAME=\"vmware\"; `,
-		`$env:BAZ=\"qux\"; $env:FOO=\"bar\"; $env:PACKER_BUILDER_TYPE=\"iso\"; $env:PACKER_BUILD_NAME=\"vmware\"; `,
-		`$env:FOO=\"bar=baz\"; $env:PACKER_BUILDER_TYPE=\"iso\"; $env:PACKER_BUILD_NAME=\"vmware\"; `,
-		`$env:FOO=\"=bar\"; $env:PACKER_BUILDER_TYPE=\"iso\"; $env:PACKER_BUILD_NAME=\"vmware\"; `,
+		`$env:PACKER_BUILDER_TYPE="iso"; $env:PACKER_BUILD_NAME="vmware"; `,
+		`$env:FOO="bar"; $env:PACKER_BUILDER_TYPE="iso"; $env:PACKER_BUILD_NAME="vmware"; `,
+		`$env:BAZ="qux"; $env:FOO="bar"; $env:PACKER_BUILDER_TYPE="iso"; $env:PACKER_BUILD_NAME="vmware"; `,
+		`$env:FOO="bar=baz"; $env:PACKER_BUILDER_TYPE="iso"; $env:PACKER_BUILD_NAME="vmware"; `,
+		`$env:FOO="=bar"; $env:PACKER_BUILDER_TYPE="iso"; $env:PACKER_BUILD_NAME="vmware"; `,
 	}
 
 	p := new(Provisioner)
@@ -571,7 +579,6 @@ func TestProvisioner_createFlattenedEnvVars_windows(t *testing.T) {
 }
 
 func TestProvision_createCommandText(t *testing.T) {
-
 	config := testConfig()
 	config["remote_path"] = "c:/Windows/Temp/script.ps1"
 	p := new(Provisioner)
@@ -586,22 +593,46 @@ func TestProvision_createCommandText(t *testing.T) {
 	// Non-elevated
 	cmd, _ := p.createCommandText()
 
-	expectedCommand := `powershell -executionpolicy bypass "& { if (Test-Path variable:global:ProgressPreference){$ProgressPreference='SilentlyContinue'};$env:PACKER_BUILDER_TYPE=\"iso\"; $env:PACKER_BUILD_NAME=\"vmware\"; &'c:/Windows/Temp/script.ps1';exit $LastExitCode }"`
-
-	if cmd != expectedCommand {
-		t.Fatalf("Expected Non-elevated command: %s, got %s", expectedCommand, cmd)
+	re := regexp.MustCompile(`powershell -executionpolicy bypass "& { if \(Test-Path variable:global:ProgressPreference\){\$ProgressPreference='SilentlyContinue'};\. \${env:SYSTEMROOT}\\Temp\\packer-env-vars-[[:alnum:]]{8}-[[:alnum:]]{4}-[[:alnum:]]{4}-[[:alnum:]]{4}-[[:alnum:]]{12}\.ps1; &'c:/Windows/Temp/script.ps1';exit \$LastExitCode }"`)
+	matched := re.MatchString(cmd)
+	if !matched {
+		t.Fatalf("Got unexpected command: %s", cmd)
 	}
 
 	// Elevated
 	p.config.ElevatedUser = "vagrant"
 	p.config.ElevatedPassword = "vagrant"
 	cmd, _ = p.createCommandText()
-	matched, _ := regexp.MatchString("powershell -executionpolicy bypass -file \"%TEMP%(.{1})packer-elevated-shell.*", cmd)
+	re = regexp.MustCompile(`powershell -executionpolicy bypass -file "%TEMP%\\packer-elevated-shell-[[:alnum:]]{8}-[[:alnum:]]{4}-[[:alnum:]]{4}-[[:alnum:]]{4}-[[:alnum:]]{12}\.ps1"`)
+	matched = re.MatchString(cmd)
 	if !matched {
 		t.Fatalf("Got unexpected elevated command: %s", cmd)
 	}
 }
 
+func TestProvision_uploadEnvVars(t *testing.T) {
+	p := new(Provisioner)
+	comm := new(packer.MockCommunicator)
+	p.communicator = comm
+
+	flattenedEnvVars := `$env:PACKER_BUILDER_TYPE="footype"; $env:PACKER_BUILD_NAME="foobuild";`
+
+	envVarPath, err := p.uploadEnvVars(flattenedEnvVars)
+	if err != nil {
+		t.Fatalf("Did not expect error: %s", err.Error())
+	}
+
+	if comm.UploadCalled != true {
+		t.Fatalf("Failed to upload env var file")
+	}
+
+	re := regexp.MustCompile(`\${env:SYSTEMROOT}\\Temp\\packer-env-vars-[[:alnum:]]{8}-[[:alnum:]]{4}-[[:alnum:]]{4}-[[:alnum:]]{4}-[[:alnum:]]{12}\.ps1`)
+	matched := re.MatchString(envVarPath)
+	if !matched {
+		t.Fatalf("Got unexpected path for env var file: %s", envVarPath)
+	}
+}
+
 func TestProvision_generateElevatedShellRunner(t *testing.T) {
 
 	// Non-elevated