diff --git a/WIN10_WinISP_SrcCode_For_MOKA_20250416_1/WinISP/BaseClass/GraphicCardI2CCtrl.cs b/WIN10_WinISP_SrcCode_For_MOKA_20250416_1/WinISP/BaseClass/GraphicCardI2CCtrl.cs
index 6ea107e..4b7f1b2 100644
--- a/WIN10_WinISP_SrcCode_For_MOKA_20250416_1/WinISP/BaseClass/GraphicCardI2CCtrl.cs
+++ b/WIN10_WinISP_SrcCode_For_MOKA_20250416_1/WinISP/BaseClass/GraphicCardI2CCtrl.cs
@@ -144,15 +144,165 @@ namespace WinISP.BaseClass
             }
         }
 
+        private readonly object _graphicsCardLock = new object();
+        private volatile bool _isDisposing = false;
+
         private void FreeGraphicsCardCtrl()
         {
-            // Free the GCHandle.
-            frmISP.WriteLog("Free the GCHandle.", "debug");
-            if (gch.IsAllocated)
-                gch.Free();
-            DisposeGraphicCardCtrl();
-            pGraphicCardCtrl = IntPtr.Zero;
-            _IsInit = false;
+            lock (_graphicsCardLock)
+            {
+                // 防止重复释放
+                if (_isDisposing)
+                {
+                    frmISP.WriteLog("Graphics card control is already being disposed, skipping.", "warn");
+                    return;
+                }
+
+                if (!_IsInit)
+                {
+                    frmISP.WriteLog("Graphics card control is not initialized, nothing to free.", "debug");
+                    return;
+                }
+
+                _isDisposing = true;
+
+                try
+                {
+                    // 第一步：释放 GCHandle
+                    FreeGCHandle();
+
+                    // 第二步：释放图形卡控制资源
+                    DisposeGraphicsCardControl();
+
+                    // 第三步：清空指针
+                    pGraphicCardCtrl = IntPtr.Zero;
+
+                    // 第四步：更新状态
+                    _IsInit = false;
+
+                    frmISP.WriteLog("Graphics card control freed successfully.", "info");
+                }
+                catch (Exception ex)
+                {
+                    frmISP.WriteLog($"Error freeing graphics card control: {ex.GetType().Name} - {ex.Message}", "error");
+                    // 即使出错也要尝试清理状态
+                    try
+                    {
+                        pGraphicCardCtrl = IntPtr.Zero;
+                        _IsInit = false;
+                    }
+                    catch (Exception cleanupEx)
+                    {
+                        frmISP.WriteLog($"Error during cleanup after exception: {cleanupEx.Message}", "error");
+                    }
+                }
+                finally
+                {
+                    _isDisposing = false;
+                }
+            }
+        }
+
+        /// <summary>
+        /// 安全释放 GCHandle
+        /// </summary>
+        private void FreeGCHandle()
+        {
+            try
+            {
+                if (gch.IsAllocated)
+                {
+                    frmISP.WriteLog("Freeing GCHandle...", "debug");
+                    gch.Free();
+                    frmISP.WriteLog("GCHandle freed successfully.", "debug");
+                }
+                else
+                {
+                    frmISP.WriteLog("GCHandle is not allocated, skipping free operation.", "debug");
+                }
+            }
+            catch (InvalidOperationException ex)
+            {
+                frmISP.WriteLog($"InvalidOperationException when freeing GCHandle: {ex.Message}", "warn");
+            }
+            catch (Exception ex)
+            {
+                frmISP.WriteLog($"Unexpected exception when freeing GCHandle: {ex.GetType().Name} - {ex.Message}", "error");
+            }
+        }
+
+        /// <summary>
+        /// 安全释放图形卡控制资源
+        /// </summary>
+        private void DisposeGraphicsCardControl()
+        {
+            try
+            {
+                if (pGraphicCardCtrl != IntPtr.Zero)
+                {
+                    frmISP.WriteLog("Disposing graphics card control...", "debug");
+                    DisposeGraphicCardCtrl();
+                    frmISP.WriteLog("Graphics card control disposed successfully.", "debug");
+                }
+                else
+                {
+                    frmISP.WriteLog("Graphics card control pointer is null, skipping dispose.", "debug");
+                }
+            }
+            catch (AccessViolationException ex)
+            {
+                frmISP.WriteLog($"AccessViolationException when disposing graphics card control: {ex.Message}", "error");
+            }
+            catch (ObjectDisposedException ex)
+            {
+                frmISP.WriteLog($"ObjectDisposedException when disposing graphics card control: {ex.Message}", "warn");
+            }
+            catch (Exception ex)
+            {
+                frmISP.WriteLog($"Unexpected exception when disposing graphics card control: {ex.GetType().Name} - {ex.Message}", "error");
+            }
+        }
+
+        /// <summary>
+        /// 验证图形卡控制是否已正确释放
+        /// </summary>
+        public bool IsGraphicsCardControlFreed()
+        {
+            lock (_graphicsCardLock)
+            {
+                return !_IsInit && pGraphicCardCtrl == IntPtr.Zero && !gch.IsAllocated;
+            }
+        }
+
+        /// <summary>
+        /// 强制清理（用于异常恢复）
+        /// </summary>
+        public void ForceCleanupGraphicsCardCtrl()
+        {
+            lock (_graphicsCardLock)
+            {
+                try
+                {
+                    frmISP.WriteLog("Performing force cleanup of graphics card control...", "warn");
+
+                    // 强制释放 GCHandle
+                    if (gch.IsAllocated)
+                    {
+                        try { gch.Free(); }
+                        catch { }
+                    }
+
+                    // 强制清空指针
+                    pGraphicCardCtrl = IntPtr.Zero;
+                    _IsInit = false;
+
+                    frmISP.WriteLog("Force cleanup completed.", "info");
+                }
+                catch (Exception ex)
+                {
+                    frmISP.WriteLog($"Error during force cleanup: {ex.Message}", "error");
+                }
+            }
         }
 
         public GraphicCardI2CCtrl()
diff --git a/WIN10_WinISP_SrcCode_For_MOKA_20250416_1/WinISP/FormISP_MSI.cs b/WIN10_WinISP_SrcCode_For_MOKA_20250416_1/WinISP/FormISP_MSI.cs
index fec742c..768a467 100644
--- a/WIN10_WinISP_SrcCode_For_MOKA_20250416_1/WinISP/FormISP_MSI.cs
+++ b/WIN10_WinISP_SrcCode_For_MOKA_20250416_1/WinISP/FormISP_MSI.cs
@@ -125,15 +125,125 @@ namespace WinISP
 
         public void CheckSingleInstance()
         {
-            Process[] thisnameprocesslist;
-            string modulename, processname;
-            Process p = Process.GetCurrentProcess();
-            modulename = p.MainModule.ModuleName.ToString();
-            processname = System.IO.Path.GetFileNameWithoutExtension(modulename);
-            thisnameprocesslist = Process.GetProcessesByName(processname);
-            if (thisnameprocesslist.Length > 1)
+            Process currentProcess = null;
+            Process[] processList = null;
+
+            try
             {
-                Application.Exit();
+                currentProcess = Process.GetCurrentProcess();
+
+                // 安全获取模块名称
+                if (currentProcess.MainModule == null)
+                {
+                    frmISP.WriteLog("Failed to get MainModule, cannot perform single instance check", "error");
+                    return;
+                }
+
+                string moduleName = currentProcess.MainModule.ModuleName;
+                string processName = System.IO.Path.GetFileNameWithoutExtension(moduleName);
+
+                frmISP.WriteLog($"Current process name: {processName}, PID: {currentProcess.Id}", "debug");
+
+                // 获取同名进程列表
+                processList = Process.GetProcessesByName(processName);
+
+                frmISP.WriteLog($"Found {processList.Length} process(es) with name '{processName}'", "debug");
+
+                // 检查是否存在多个实例
+                if (processList.Length > 1)
+                {
+                    frmISP.WriteLog($"Multiple instances detected ({processList.Length}). Exiting application.", "warn");
+
+                    // 可选：激活已存在的实例窗口
+                    ActivateExistingInstance(processList, currentProcess.Id);
+
+                    Application.Exit();
+                }
+                else
+                {
+                    frmISP.WriteLog("Single instance check passed. Application is running as the only instance.", "debug");
+                }
+            }
+            catch (System.ComponentModel.Win32Exception ex)
+            {
+                frmISP.WriteLog($"Win32Exception in CheckSingleInstance: {ex.Message}", "error");
+            }
+            catch (UnauthorizedAccessException ex)
+            {
+                frmISP.WriteLog($"UnauthorizedAccessException in CheckSingleInstance: {ex.Message}", "error");
+            }
+            catch (Exception ex)
+            {
+                frmISP.WriteLog($"Unexpected exception in CheckSingleInstance: {ex.GetType().Name} - {ex.Message}", "error");
+            }
+            finally
+            {
+                // 释放 Process 资源
+                if (processList != null)
+                {
+                    foreach (var p in processList)
+                    {
+                        p?.Dispose();
+                    }
+                }
+                currentProcess?.Dispose();
+            }
+        }
+
+        /// <summary>
+        /// 尝试激活已存在的应用实例窗口
+        /// </summary>
+        private void ActivateExistingInstance(Process[] processList, int currentPid)
+        {
+            try
+            {
+                foreach (var process in processList)
+                {
+                    // 跳过当前进程
+                    if (process.Id == currentPid)
+                        continue;
+
+                    // 尝试获取主窗口句柄
+                    if (process.MainWindowHandle != IntPtr.Zero)
+                    {
+                        // 恢复窗口（如果最小化）
+                        if (IsWindowMinimized(process.MainWindowHandle))
+                        {
+                            ShowWindow(process.MainWindowHandle, 9); // SW_RESTORE
+                        }
+
+                        // 激活窗口
+                        SetForegroundWindow(process.MainWindowHandle);
+                        frmISP.WriteLog($"Activated existing instance (PID: {process.Id})", "info");
+                        return;
+                    }
+                }
+            }
+            catch (Exception ex)
+            {
+                frmISP.WriteLog($"Failed to activate existing instance: {ex.Message}", "warn");
+            }
+        }
+
+        // Windows API 声明
+        [System.Runtime.InteropServices.DllImport("user32.dll")]
+        private static extern bool SetForegroundWindow(IntPtr hWnd);
+
+        [System.Runtime.InteropServices.DllImport("user32.dll")]
+        private static extern bool ShowWindow(IntPtr hWnd, int nCmdShow);
+
+        [System.Runtime.InteropServices.DllImport("user32.dll")]
+        private static extern bool IsIconic(IntPtr hWnd);
+
+        private bool IsWindowMinimized(IntPtr hWnd)
+        {
+            try
+            {
+                return IsIconic(hWnd);
+            }
+            catch
+            {
+                return false;
             }
         }