Index: branches/RC/core/install/step_templates/upgrade_modules.tpl
===================================================================
diff -u -N -r9988 -r10832
--- branches/RC/core/install/step_templates/upgrade_modules.tpl	(.../upgrade_modules.tpl)	(revision 9988)
+++ branches/RC/core/install/step_templates/upgrade_modules.tpl	(.../upgrade_modules.tpl)	(revision 10832)
@@ -1,28 +1,51 @@
 <?php
 	ob_start();
 ?>
-<tr class="table-color2">  
+<tr class="table-color2">
 	<td class="text" colspan="2" valign="middle">
 		<table cellpadding="0" cellspacing="0">
 			<tr>
-				<td><input type="checkbox" %3$s name="modules[]" id="module_%1$s" value="%1$s"/></td>
-				<td><label for="module_%1$s">%2$s</label></td>
+				<td valign="top">
+					<input type="checkbox" %3$s name="modules[]" id="module_%1$s" value="%1$s"/>
+				</td>
+				<td valign="top">
+					<label for="module_%1$s">%2$s</label>
+					<div style="font-weight: bold; color: red;">%4$s</div>
+				</td>
 			</tr>
 		</table>
 	</td>
 </tr>
 <?php
 	$module_tpl = ob_get_clean();
 
+	$selected = $this->GetVar('modules');
 	$modules = $this->GetUpgradableModules();
 	foreach ($modules as $module_name => $module_params) {
-		$module_title = $module_name.' ('.$module_params['Version'].' to '.$module_params['ToVersion'].')';
+		$module_name = strtolower($module_name);
+		$upgrade_versions = Array (
+			$module_params['Version'],
+			$module_params['ToVersion'],
+		);
+		$prerequisites_errors = $this->toolkit->CheckPrerequisites($module_params['Path'], $upgrade_versions, 'upgrade');
+
+		$module_title = $this->toolkit->getModuleName($module_name).' ('.$module_params['Version'].' to '.$module_params['ToVersion'].')';
 		if ($this->Application->isDebugMode()) {
 			$module_title .= ' [from: '.$module_params['FromVersion'].']';
 		}
-		$selected = $this->GetVar('modules');
-		$checked = in_array($module_name, $selected) ? 'checked="checked"' : '';
-		echo sprintf($module_tpl, $module_name, $module_title, $checked);
+
+		if ($prerequisites_errors) {
+			// disable checkbox, when some of prerequisites not passed
+			$checked = 'disabled';
+		}
+		else {
+			// preserve user selected checked status
+			$checked = in_array($module_name, $selected) ? 'checked="checked"' : '';
+		}
+
+		$error_msg = $prerequisites_errors ? implode('<br />', $prerequisites_errors) : '';
+
+		echo sprintf($module_tpl, $module_name, $module_title, $checked, $error_msg);
 	}
 ?>
 <tr class="table-color1">