diff --git a/src/Misc/CSharpScriptHost.cs b/src/Misc/CSharpScriptHost.cs
index 7470064..440c0a6 100644
--- a/src/Misc/CSharpScriptHost.cs
+++ b/src/Misc/CSharpScriptHost.cs
@@ -1,12 +1,9 @@
 
-using System;
 using System.CodeDom.Compiler;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
 using System.Reflection;
-using System.Security.Cryptography;
-using System.Text;
 
 using Microsoft.CSharp;
 
@@ -28,7 +25,7 @@ namespace mpvnet
         static void Execute(string file)
         {
             string code = File.ReadAllText(file);
-            string filename = Path.GetFileNameWithoutExtension(file) + " " + GetMD5(code) + ".dll";
+            string filename = Path.GetFileNameWithoutExtension(file) + " " + StringHelp.GetMD5Hash(code) + ".dll";
             string outputFile = Path.Combine(Path.GetTempPath(), filename);
 
             if (!File.Exists(outputFile))
@@ -70,15 +67,5 @@ namespace mpvnet
             if (errors.Count() > 0)
                 Terminal.WriteError(string.Join(BR2, errors), Path.GetFileName(file));
         }
-
-        static string GetMD5(string code)
-        {
-            using (MD5 md5 = MD5.Create())
-            {
-                byte[] inputBuffer = Encoding.UTF8.GetBytes(code);
-                byte[] hashBuffer = md5.ComputeHash(inputBuffer);
-                return BitConverter.ToString(md5.ComputeHash(inputBuffer)).Replace("-", "");
-            }
-        }
     }
 }
diff --git a/src/Misc/Help.cs b/src/Misc/Help.cs
index e43bfa0..7e04cc3 100644
--- a/src/Misc/Help.cs
+++ b/src/Misc/Help.cs
@@ -4,6 +4,8 @@ using System.Diagnostics;
 using System.Drawing;
 using System.IO;
 using System.Linq;
+using System.Security.Cryptography;
+using System.Text;
 using System.Windows.Forms;
 
 using Microsoft.Win32;
@@ -12,6 +14,19 @@ using static mpvnet.Global;
 
 namespace mpvnet
 {
+    public static class StringHelp
+    {
+        public static string GetMD5Hash(string txt)
+        {
+            using (MD5 md5 = MD5.Create())
+            {
+                byte[] inputBuffer = Encoding.UTF8.GetBytes(txt);
+                byte[] hashBuffer = md5.ComputeHash(inputBuffer);
+                return BitConverter.ToString(md5.ComputeHash(inputBuffer)).Replace("-", "");
+            }
+        }
+    }
+
     public static class FileHelp
     {
         public static void Delete(string path)
diff --git a/src/Misc/Program.cs b/src/Misc/Program.cs
index 37c4a47..8203a3b 100644
--- a/src/Misc/Program.cs
+++ b/src/Misc/Program.cs
@@ -38,7 +38,7 @@ namespace mpvnet
                 }
 
                 App.Init();
-                Mutex mutex = new Mutex(true, "mpvnetProcessInstance", out bool isFirst);
+                Mutex mutex = new Mutex(true, StringHelp.GetMD5Hash(App.ConfPath), out bool isFirst);
 
                 if ((App.ProcessInstance == "single" || App.ProcessInstance == "queue") && !isFirst)
                 {
diff --git a/src/WinForms/MainForm.cs b/src/WinForms/MainForm.cs
index f9c378c..c5a38c1 100644
--- a/src/WinForms/MainForm.cs
+++ b/src/WinForms/MainForm.cs
@@ -815,7 +815,7 @@ namespace mpvnet
             }
             else if (Environment.TickCount - LastCursorChanged > 1500 &&
                 !IsMouseInOSC() && ClientRectangle.Contains(PointToClient(MousePosition)) &&
-                Form.ActiveForm == this && !ContextMenu.Visible)
+                ActiveForm == this && !ContextMenu.Visible)
 
                 CursorHelp.Hide();
         }