diff --git a/typo3/install/index.php b/typo3/install/index.php
index 32a81de..d0daaff 100755
--- a/typo3/install/index.php
+++ b/typo3/install/index.php
@@ -83,34 +83,84 @@ if (1==2 || !is_file($enableInstallToolFile)) {
 
 		// Get the template file
 	$template = @file_get_contents($PATH_site . '/typo3/templates/install.html');
-		// Define the markers content
-	$markers = array(
-		'styleSheet' => $stylesheet,
-		'javascript' => $javascript,
-		'title' => 'The Install Tool is locked',
-		'content' => '
-			<p>
-				To enable the Install Tool, the file ENABLE_INSTALL_TOOL must be created.
-			</p>
-			<ul>
-				<li>
-					In the typo3conf/ folder, create a file named ENABLE_INSTALL_TOOL. The file name is
-					case sensitive, but the file itself can simply be an empty file.
-				</li>
-				<li class="t3-install-locked-user-settings">
-					Alternatively, in the Backend, go to <a href="javascript:top.goToModule(\'user_setup\',1);">User tools &gt; User settings</a>
-					and let TYPO3 create this file for you. When you\'re finished, you can also visit
-					<a href="javascript:top.goToModule(\'user_setup\',1);">User tools &gt; User settings</a> and delete the file from there.
-				</li>
-			</ul>
-			<p>
-				For security reasons, it is highly recommended that you either rename or delete the file after the operation is finished.
-			</p>
-			<p>
-				As an additional security measure, if the file is older than one hour, TYPO3 will automatically delete it.
-			</p>
-		'
+
+
+		// check the write permissions of the following directories first
+		// this jumps in as the first message during installation process to force the user to fix this at first
+	$writeDirectories = array(
+		'fileadmin',
+		'typo3conf',
+		'typo3temp',
+		'uploads',
 	);
+
+		// saves all directories with insufficient permissions
+	$missingWritePermissions = array();
+
+	foreach ($writeDirectories as $directory) {
+		if (!is_writable($PATH_site . '/' . $directory . '/')) {
+			$missingWritePermissions[] = $directory;
+		}
+	}
+
+		// show warning, if one of the directories lacks write permissions
+	if (count($missingWritePermissions)) {
+		$markers = array(
+			'styleSheet' => $stylesheet,
+			'javascript' => $javascript,
+			'title' => 'Insufficient permissions',
+			'content' => '
+				<p>
+					To work properly, the following directories and their contents must be writable for the user,
+					under which the web server is running:
+				</p>
+				<ul>
+					<li>
+					' . implode('/</li><li>', $missingWritePermissions) . '
+					</li>
+				</ul>
+				<p>
+					On most systems, this can be achieved by executing the following commands:
+				</p>
+				<pre>' .
+					implode(array_map(
+						function($directory) use ($PATH_site) {
+							return 'chown -R 777 ' . $PATH_site . '/' . $directory . '/<br />';
+						},
+						$missingWritePermissions
+					)) . '</pre>
+			',
+		);
+	} else {
+			// display the "Install Tool is locked" message
+		$markers = array(
+			'styleSheet' => $stylesheet,
+			'javascript' => $javascript,
+			'title' => 'The Install Tool is locked',
+			'content' => '
+				<p>
+					To enable the Install Tool, the file ENABLE_INSTALL_TOOL must be created.
+				</p>
+				<ul>
+					<li>
+						In the typo3conf/ folder, create a file named ENABLE_INSTALL_TOOL. The file name is
+						case sensitive, but the file itself can simply be an empty file.
+					</li>
+					<li class="t3-install-locked-user-settings">
+						Alternatively, in the Backend, go to <a href="javascript:top.goToModule(\'user_setup\',1);">User tools &gt; User settings</a>
+						and let TYPO3 create this file for you. When you\'re finished, you can also visit
+						<a href="javascript:top.goToModule(\'user_setup\',1);">User tools &gt; User settings</a> and delete the file from there.
+					</li>
+				</ul>
+				<p>
+					For security reasons, it is highly recommended that you either rename or delete the file after the operation is finished.
+				</p>
+				<p>
+					As an additional security measure, if the file is older than one hour, TYPO3 will automatically delete it.
+				</p>
+			'
+		);
+	}
 		// Fill the markers
 	$content = t3lib_parsehtml::substituteMarkerArray(
 		$template,