diff --git a/setup/wizardsteps/WizStepDataAudit.php b/setup/wizardsteps/WizStepDataAudit.php
index 2b63be2d8..a7f6d2b60 100644
--- a/setup/wizardsteps/WizStepDataAudit.php
+++ b/setup/wizardsteps/WizStepDataAudit.php
@@ -69,7 +69,7 @@ class WizStepDataAudit extends WizStepInstall
 
 		$aInstallParams = $this->BuildConfig();
 
-		$this->AddProgressBar($oPage);
+		$this->AddProgressBar($oPage, 'Progress of the verification');
 
 		$sJSONData = json_encode($aInstallParams);
 		$oPage->add('<input type="hidden" id="installer_parameters" value="'.utils::EscapeHtml($sJSONData).'"/>');
@@ -78,17 +78,19 @@ class WizStepDataAudit extends WizStepInstall
 		$oPage->add('<input type="hidden" id="authent_token" value="'.$sAuthentToken.'"/>');
 		$sApplicationUrl = $this->oWizard->GetParameter('application_url').'pages/exec.php?exec_module=combodo-data-feature-removal&exec_page=index.php';
 		$oPage->add('<input type="hidden" id="application_url" value="'.$sApplicationUrl.'"/>');
-
 		if (!$this->CheckDependencies()) {
 			$oPage->error($this->sDependencyIssue);
-		}
-
-		$oPage->add_ready_script(
-			<<<JS
+			$oPage->add_ready_script(<<<JS
+	$("#wiz_form").data("installation_status", "error");
+	document.getElementById("setup_msg").innerText = "Unmet dependencies";
+JS);
+		} else {
+			$oPage->add_ready_script(<<<JS
 	$("#wiz_form").data("installation_status", "not started");
 	ExecuteStep("");
-JS
-		);
+JS);
+		}
+
 	}
 
 	protected function AddProgressErrorScript($oPage, $aRes)
diff --git a/setup/wizardsteps/WizStepInstall.php b/setup/wizardsteps/WizStepInstall.php
index b0d878bd3..615832f56 100644
--- a/setup/wizardsteps/WizStepInstall.php
+++ b/setup/wizardsteps/WizStepInstall.php
@@ -58,9 +58,9 @@ class WizStepInstall extends AbstractWizStepInstall
 		return new WizardState(WizStepDone::class);
 	}
 
-	protected function AddProgressBar(WebPage $oPage)
+	protected function AddProgressBar(WebPage $oPage, string $sTitle = 'Progress of the operations')
 	{
-		$oPage->add('<fieldset id="installation_progress"><legend>Progress of the installation</legend>');
+		$oPage->add('<fieldset id="installation_progress"><legend>'.$sTitle.'</legend>');
 		$oPage->add('<div id="progress_content">');
 		$oPage->LinkScriptFromAppRoot('setup/jquery.progression.js');
 		$oPage->add('<p class="center"><span id="setup_msg">Ready to start...</span></p><div style="display:block;margin-left: auto; margin-right:auto;" id="progress">0%</div>');
@@ -74,7 +74,7 @@ class WizStepInstall extends AbstractWizStepInstall
 	{
 
 		$aInstallParams = $this->BuildConfig();
-		$this->AddProgressBar($oPage);
+		$this->AddProgressBar($oPage, 'Progress of the installation');
 
 		$sJSONData = json_encode($aInstallParams);
 		$oPage->add('<input type="hidden" id="installer_parameters" value="'.utils::EscapeHtml($sJSONData).'"/>');
@@ -136,6 +136,7 @@ EOF
 			$oPage->add_ready_script(
 				<<<EOF
 	$("#wiz_form").data("installation_status", "error");
+	$("#progress .progress").addClass('progress-error');
 	WizardUpdateButtons();
 	$('#setup_error').html('$sMessage').show();
 EOF
diff --git a/setup/wizardsteps/WizStepInstallOrUpgrade.php b/setup/wizardsteps/WizStepInstallOrUpgrade.php
index 40f8bf634..7a2db6d47 100644
--- a/setup/wizardsteps/WizStepInstallOrUpgrade.php
+++ b/setup/wizardsteps/WizStepInstallOrUpgrade.php
@@ -126,6 +126,7 @@ HTML
 		);
 
 		$sAuthentToken = $this->oWizard->GetParameter('authent', '');
+		$oPage->add('</div>');
 		$oPage->add('<input type="hidden" id="authent_token" value="'.$sAuthentToken.'"/>');
 		//$oPage->add('</fieldset>');
 		$oPage->add_ready_script(
diff --git a/setup/wizardsteps/WizStepModulesChoice.php b/setup/wizardsteps/WizStepModulesChoice.php
index 5dc762dd4..0a0f6b875 100644
--- a/setup/wizardsteps/WizStepModulesChoice.php
+++ b/setup/wizardsteps/WizStepModulesChoice.php
@@ -680,10 +680,14 @@ EOF
 		if ($bMissingFromDisk) {
 			$bDisabled = true;
 			$bChecked = false;
-		} elseif ($bMandatory || $bInstalled && !$bCanBeUninstalled) {
+		} elseif ($bMandatory) {
 			$bDisabled = true;
 			$bChecked = true;
+		} elseif ($bInstalled && !$bCanBeUninstalled && !$bDisableUninstallCheck) {
+			$bChecked = true;
+			$bDisabled = true;
 		}
+
 		if ($bAllDisabled) {
 			$bDisabled = true;
 		}
diff --git a/tests/php-unit-tests/unitary-tests/setup/WizStepModulesChoiceTest.php b/tests/php-unit-tests/unitary-tests/setup/WizStepModulesChoiceTest.php
index 9d21471de..039215a8c 100644
--- a/tests/php-unit-tests/unitary-tests/setup/WizStepModulesChoiceTest.php
+++ b/tests/php-unit-tests/unitary-tests/setup/WizStepModulesChoiceTest.php
@@ -39,6 +39,7 @@ class WizStepModulesChoiceTest extends ItopTestCase
 					'uninstallable' => true,
 				],
 				'bCurrentSelected' => false,
+				'bDisableUninstallChecks' => false,
 				'aExpectedFlags' => [
 					'uninstallable' => true,
 					'missing' => false,
@@ -59,6 +60,7 @@ class WizStepModulesChoiceTest extends ItopTestCase
 					'uninstallable' => true,
 				],
 				'bCurrentSelected' => true,
+				'bDisableUninstallChecks' => false,
 				'aExpectedFlags' => [
 					'uninstallable' => true,
 					'missing' => false,
@@ -77,6 +79,7 @@ class WizStepModulesChoiceTest extends ItopTestCase
 					'uninstallable' => true,
 				],
 				'bCurrentSelected' => false,
+				'bDisableUninstallChecks' => false,
 				'aExpectedFlags' => [
 					'uninstallable' => true,
 					'missing' => true,
@@ -95,6 +98,7 @@ class WizStepModulesChoiceTest extends ItopTestCase
 					'uninstallable' => true,
 				],
 				'bCurrentSelected' => false,
+				'bDisableUninstallChecks' => false,
 				'aExpectedFlags' => [
 					'uninstallable' => true,
 					'missing' => true,
@@ -113,6 +117,7 @@ class WizStepModulesChoiceTest extends ItopTestCase
 					'uninstallable' => false,
 				],
 				'bCurrentSelected' => false,
+				'bDisableUninstallChecks' => false,
 				'aExpectedFlags' => [
 					'uninstallable' => false,
 					'missing' => true,
@@ -133,6 +138,7 @@ class WizStepModulesChoiceTest extends ItopTestCase
 					'uninstallable' => true,
 				],
 				'bCurrentSelected' => false,
+				'bDisableUninstallChecks' => false,
 				'aExpectedFlags' => [
 					'uninstallable' => true,
 					'missing' => false,
@@ -153,6 +159,7 @@ class WizStepModulesChoiceTest extends ItopTestCase
 					'uninstallable' => false,
 				],
 				'bCurrentSelected' => false,
+				'bDisableUninstallChecks' => false,
 				'aExpectedFlags' => [
 					'uninstallable' => false,
 					'missing' => false,
@@ -161,6 +168,27 @@ class WizStepModulesChoiceTest extends ItopTestCase
 					'checked' => true,
 				],
 			],
+			'An installed non uninstallable extension should be enabled if the "disable uninstallation check" flag is set' => [
+				'aExtensionsOnDiskOrDb' => [
+					'itop-ext1' => [
+						'installed' => true,
+					],
+				],
+				'aWizardStepDefinition' => [
+					'extension_code' => 'itop-ext1',
+					'mandatory' => false,
+					'uninstallable' => false,
+				],
+				'bCurrentSelected' => true,
+				'bDisableUninstallChecks' => true,
+				'aExpectedFlags' => [
+					'uninstallable' => false,
+					'missing' => false,
+					'installed' => true,
+					'disabled' => false,
+					'checked' => true,
+				],
+			],
 			'A mandatory extension should be checked and disabled' => [
 				'aExtensionsOnDiskOrDb' => [
 					'itop-ext1' => [
@@ -173,6 +201,28 @@ class WizStepModulesChoiceTest extends ItopTestCase
 					'uninstallable' => true,
 				],
 				'bCurrentSelected' => false,
+				'bDisableUninstallChecks' => false,
+				'aExpectedFlags' => [
+					'uninstallable' => true,
+					'missing' => false,
+					'installed' => false,
+					'disabled' => true,
+					'checked' => true,
+				],
+			],
+			'A mandatory extension should be checked and disabled even if the "disable uninstallation check" flag is set' => [
+				'aExtensionsOnDiskOrDb' => [
+					'itop-ext1' => [
+						'installed' => false,
+					],
+				],
+				'aWizardStepDefinition' => [
+					'extension_code' => 'itop-ext1',
+					'mandatory' => true,
+					'uninstallable' => true,
+				],
+				'bCurrentSelected' => false,
+				'bDisableUninstallChecks' => true,
 				'aExpectedFlags' => [
 					'uninstallable' => true,
 					'missing' => false,
@@ -205,6 +255,7 @@ class WizStepModulesChoiceTest extends ItopTestCase
 					],
 				],
 				'bCurrentSelected' => false,
+				'bDisableUninstallChecks' => false,
 				'aExpectedFlags' => [
 					'uninstallable' => true,
 					'missing' => false,
@@ -237,6 +288,7 @@ class WizStepModulesChoiceTest extends ItopTestCase
 					],
 				],
 				'bCurrentSelected' => false,
+				'bDisableUninstallChecks' => false,
 				'aExpectedFlags' => [
 					'uninstallable' => true,
 					'missing' => false,
@@ -269,6 +321,7 @@ class WizStepModulesChoiceTest extends ItopTestCase
 					],
 				],
 				'bCurrentSelected' => false,
+				'bDisableUninstallChecks' => false,
 				'aExpectedFlags' => [
 					'uninstallable' => true,
 					'missing' => false,
@@ -301,6 +354,7 @@ class WizStepModulesChoiceTest extends ItopTestCase
 					],
 				],
 				'bCurrentSelected' => false,
+				'bDisableUninstallChecks' => false,
 				'aExpectedFlags' => [
 					'uninstallable' => true,
 					'missing' => false,
@@ -315,10 +369,10 @@ class WizStepModulesChoiceTest extends ItopTestCase
 	/**
 	 * @dataProvider ProviderComputeChoiceFlags
 	 */
-	public function testComputeChoiceFlags($aExtensionsOnDiskOrDb, $aWizardStepDefinition, $bIsCurrentSelected, $aExpectedFlags)
+	public function testComputeChoiceFlags($aExtensionsOnDiskOrDb, $aWizardStepDefinition, $bIsCurrentSelected, $bDisableUninstallChecks, $aExpectedFlags)
 	{
 		$this->oStep->setExtensionMap(iTopExtensionsMapFake::createFromArray($aExtensionsOnDiskOrDb));
-		$aFlags = $this->oStep->ComputeChoiceFlags($aWizardStepDefinition, '_0', $bIsCurrentSelected ? ['_0' => '_0'] : [], false, false, true);
+		$aFlags = $this->oStep->ComputeChoiceFlags($aWizardStepDefinition, '_0', $bIsCurrentSelected ? ['_0' => '_0'] : [], false, $bDisableUninstallChecks, true);
 		$this->assertEquals($aExpectedFlags, $aFlags);
 	}