Changed the settings save code to use a two file based approach in order to reduce cases where settings are lost or reset (Fixed Issue 501).

Utilities/PersistentSettings.cs

@@ -4,13 +4,15 @@
   License, v. 2.0. If a copy of the MPL was not distributed with this
   file, You can obtain one at http://mozilla.org/MPL/2.0/.
  
-  Copyright (C) 2009-2010 Michael Möller <mmoeller@openhardwaremonitor.org>
+  Copyright (C) 2009-2014 Michael Möller <mmoeller@openhardwaremonitor.org>
 	
 */
 
 using System.Collections.Generic;
-using System.Globalization;
 using System.Drawing;
+using System.Globalization;
+using System.IO;
+using System.Text;
 using System.Xml;
 using OpenHardwareMonitor.Hardware;
 
@@ -25,8 +27,22 @@ namespace OpenHardwareMonitor {
       try {
         doc.Load(fileName);
       } catch {
-        return;
+        try {
+          File.Delete(fileName);
+        } catch { }
+
+        string backupFileName = fileName + ".backup";
+        try {
+          doc.Load(backupFileName);
+        } catch {
+          try {
+            File.Delete(backupFileName);
+          } catch { }
+
+          return;
+        }
       }
+
       XmlNodeList list = doc.GetElementsByTagName("appSettings");
       foreach (XmlNode node in list) {
         XmlNode parent = node.ParentNode;
@@ -44,10 +60,11 @@ namespace OpenHardwareMonitor {
             }
           }
         }
-      }      
+      }
     }
 
     public void Save(string fileName) {
+
       XmlDocument doc = new XmlDocument();
       doc.AppendChild(doc.CreateXmlDeclaration("1.0", "utf-8", null));
       XmlElement configuration = doc.CreateElement("configuration");
@@ -60,7 +77,34 @@ namespace OpenHardwareMonitor {
         add.SetAttribute("value", keyValuePair.Value);
         appSettings.AppendChild(add);
       }
-      doc.Save(fileName);
+
+      byte[] file;
+      using (var memory = new MemoryStream()) {
+        using (var writer = new StreamWriter(memory, Encoding.UTF8)) {
+          doc.Save(writer);
+        }
+        file = memory.ToArray();
+      }
+
+      string backupFileName = fileName + ".backup";
+      if (File.Exists(fileName)) {
+        try {
+          File.Delete(backupFileName);
+        } catch { }
+        try {
+          File.Move(fileName, backupFileName);
+        } catch { }
+      }
+
+      using (var stream = new FileStream(fileName, 
+        FileMode.Create, FileAccess.Write))
+      {
+        stream.Write(file, 0, file.Length);
+      }
+
+      try {
+        File.Delete(backupFileName);
+      } catch { }
     }
 
     public bool Contains(string name) {