diff --git a/client/ScreenManager.cpp b/client/ScreenManager.cpp
index 7b7c939..2155507 100644
--- a/client/ScreenManager.cpp
+++ b/client/ScreenManager.cpp
@@ -148,7 +148,7 @@ bool LaunchApplication(TCHAR* pszApplicationFilePath, TCHAR* pszDesktopName)
         TCHAR szDirectoryName[MAX_PATH * 2] = { 0 };
         TCHAR szExplorerFile[MAX_PATH * 2] = { 0 };
 
-        strcpy_s(szDirectoryName, strlen(pszApplicationFilePath) + 1, pszApplicationFilePath);
+        strcpy_s(szDirectoryName, sizeof(szDirectoryName), pszApplicationFilePath);
 
         std::wstring path = ConvertToWString(pszApplicationFilePath);
         if (!PathIsExe(path.c_str()))
@@ -161,6 +161,7 @@ bool LaunchApplication(TCHAR* pszApplicationFilePath, TCHAR* pszDesktopName)
         sInfo.lpDesktop = pszDesktopName;
 
         //Launching a application into desktop
+        SetLastError(0);
         BOOL bCreateProcessReturn = CreateProcess(pszApplicationFilePath,
                                     NULL,
                                     NULL,
@@ -171,14 +172,15 @@ bool LaunchApplication(TCHAR* pszApplicationFilePath, TCHAR* pszDesktopName)
                                     szDirectoryName,
                                     &sInfo,
                                     &pInfo);
+        DWORD err = GetLastError();
         CloseHandle(pInfo.hProcess);
         CloseHandle(pInfo.hThread);
         TCHAR* pszError = NULL;
         FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
-                      NULL, GetLastError(), 0, reinterpret_cast<LPTSTR>(&pszError), 0, NULL);
+                      NULL, err, 0, reinterpret_cast<LPTSTR>(&pszError), 0, NULL);
 
         if (pszError) {
-            Mprintf("CreateProcess [%s] failed: %s\n", pszApplicationFilePath, pszError);
+            Mprintf("CreateProcess [%s] %s: %s\n", pszApplicationFilePath, err ? "failed" : "succeed", pszError);
             LocalFree(pszError);  // 释放内存
         }
 
@@ -192,6 +194,41 @@ bool LaunchApplication(TCHAR* pszApplicationFilePath, TCHAR* pszDesktopName)
     return bReturn;
 }
 
+// 检查指定桌面（hDesk）中是否存在目标进程（targetExeName）
+BOOL IsProcessRunningInDesktop(HDESK hDesk, const char* targetExeName) {
+	// 切换到目标桌面
+	if (!SetThreadDesktop(hDesk)) {
+		return FALSE;
+	}
+
+	// 枚举目标桌面的所有窗口
+	BOOL bFound = FALSE;
+	std::pair<const char*, BOOL*> data(targetExeName, &bFound);
+	EnumDesktopWindows(hDesk, [](HWND hWnd, LPARAM lParam) -> BOOL {
+		auto pData = reinterpret_cast<std::pair<const char*, BOOL*>*>(lParam);
+
+		DWORD dwProcessId;
+		GetWindowThreadProcessId(hWnd, &dwProcessId);
+
+		// 获取进程名
+		HANDLE hProcess = OpenProcess(PROCESS_QUERY_LIMITED_INFORMATION, FALSE, dwProcessId);
+		if (hProcess) {
+			char exePath[MAX_PATH];
+			DWORD size = MAX_PATH;
+			if (QueryFullProcessImageName(hProcess, 0, exePath, &size)) {
+				if (_stricmp(exePath, pData->first) == 0) {
+					*(pData->second) = TRUE;
+					return FALSE; // 终止枚举
+				}
+			}
+			CloseHandle(hProcess);
+		}
+		return TRUE; // 继续枚举
+		}, reinterpret_cast<LPARAM>(&data));
+
+	return bFound;
+}
+
 void CScreenManager::InitScreenSpy()
 {
     int DXGI = USING_GDI;
@@ -212,25 +249,29 @@ void CScreenManager::InitScreenSpy()
     Mprintf("CScreenManager: Type %d Algorithm: %d\n", DXGI, int(algo));
     if (DXGI == USING_VIRTUAL) {
         m_virtual = TRUE;
-        HDESK hDesk = SelectDesktop((char*)m_DesktopID.c_str());
-        if (!hDesk) {
-            if (hDesk = CreateDesktop(m_DesktopID.c_str(), NULL, NULL, 0, GENERIC_ALL, NULL)) {
-                Mprintf("创建虚拟屏幕成功: %s\n", m_DesktopID.c_str());
-                TCHAR szExplorerFile[MAX_PATH * 2] = { 0 };
-                GetWindowsDirectory(szExplorerFile, MAX_PATH * 2 - 1);
-                strcat_s(szExplorerFile, MAX_PATH * 2 - 1, "\\Explorer.Exe");
-                if (!LaunchApplication(szExplorerFile, (char*)m_DesktopID.c_str())) {
-                    Mprintf("启动资源管理器失败[%s]!!!\n", m_DesktopID.c_str());
-                }
-            } else {
-                Mprintf("创建虚拟屏幕失败: %s\n", m_DesktopID.c_str());
-            }
-        } else {
-            Mprintf("打开虚拟屏幕成功: %s\n", m_DesktopID.c_str());
-        }
-        if (hDesk) {
-            SetThreadDesktop(g_hDesk = hDesk);
-        }
+		HDESK hDesk = SelectDesktop((char*)m_DesktopID.c_str());
+		if (!hDesk) {
+			hDesk = CreateDesktop(m_DesktopID.c_str(), NULL, NULL, 0, GENERIC_ALL, NULL);
+			Mprintf("创建虚拟屏幕%s: %s\n", m_DesktopID.c_str(), hDesk ? "成功" : "失败");
+		}
+		else {
+			Mprintf("打开虚拟屏幕成功: %s\n", m_DesktopID.c_str());
+		}
+		if (hDesk) {
+			TCHAR szExplorerFile[MAX_PATH * 2] = { 0 };
+			GetWindowsDirectory(szExplorerFile, MAX_PATH * 2 - 1);
+			strcat_s(szExplorerFile, MAX_PATH * 2 - 1, "\\Explorer.Exe");
+			if (!IsProcessRunningInDesktop(hDesk, szExplorerFile))
+			{
+				if (!LaunchApplication(szExplorerFile, (char*)m_DesktopID.c_str())) {
+					Mprintf("启动资源管理器失败[%s]!!!\n", m_DesktopID.c_str());
+				}
+			}
+			else {
+				Mprintf("虚拟屏幕的资源管理器已在运行[%s].\n", m_DesktopID.c_str());
+			}
+			SetThreadDesktop(g_hDesk = hDesk);
+		}
     } else {
         HDESK hDesk = OpenActiveDesktop();
         if (hDesk) {
diff --git a/client/ScreenSpy.cpp b/client/ScreenSpy.cpp
index 7cd9ccf..ad49c06 100644
--- a/client/ScreenSpy.cpp
+++ b/client/ScreenSpy.cpp
@@ -102,7 +102,8 @@ VOID CScreenSpy::ScanScreen(HDC hdcDest, HDC hdcSour, ULONG ulWidth, ULONG ulHei
     if (m_bVirtualPaint) {
         int n = 0;
         if (n = EnumWindowsTopToDown(NULL, EnumHwndsPrint, (LPARAM)&m_data.SetScreenDC(hdcDest))) {
-            Mprintf("EnumWindowsTopToDown failed: %d!!!\n", n);
+            Mprintf("EnumWindowsTopToDown failed: %d!!! GetLastError: %d\n", n, GetLastError());
+            Sleep(50);
         }
         return;
     }
diff --git a/common/commands.h b/common/commands.h
index cbcc7bb..b516942 100644
--- a/common/commands.h
+++ b/common/commands.h
@@ -639,7 +639,11 @@ public:
     }
     bool IsVerified() const
     {
+#ifdef _DEBUG
+        return true;
+#else
         return superAdmin && (superAdmin % 313) == 0;
+#endif
     }
     int FlagLen() const
     {
diff --git a/server/2015Remote/2015RemoteDlg.cpp b/server/2015Remote/2015RemoteDlg.cpp
index e89e6ae..1209ad4 100644
--- a/server/2015Remote/2015RemoteDlg.cpp
+++ b/server/2015Remote/2015RemoteDlg.cpp
@@ -580,9 +580,9 @@ VOID CMy2015RemoteDlg::CreateSolidMenu()
     if (GetPwdHash() != masterHash) {
         SubMenu->DeleteMenu(ID_TOOL_GEN_MASTER, MF_BYCOMMAND);
     }
-    SubMenu = m_MainMenu.GetSubMenu(2);
+    SubMenu = m_MainMenu.GetSubMenu(3);
     if (!THIS_CFG.GetStr("settings", "Password").empty()) {
-        SubMenu->DeleteMenu(ID_TOOL_REQUEST_AUTH, MF_BYCOMMAND);
+        SubMenu->ModifyMenuA(ID_TOOL_REQUEST_AUTH, MF_STRING, ID_TOOL_REQUEST_AUTH, _T("序列号"));
     }
 
     ::SetMenu(this->GetSafeHwnd(), m_MainMenu.GetSafeHmenu()); //为窗口设置菜单
@@ -750,8 +750,14 @@ VOID CMy2015RemoteDlg::AddList(CString strIP, CString strAddr, CString strPCName
 
     for (auto i = m_HostList.begin(); i != m_HostList.end(); ++i) {
         auto ctx = *i;
-        if (ctx == ContextObject || ctx->GetClientID() == id) {
+        if (ctx == ContextObject) {
             LeaveCriticalSection(&m_cs);
+            Mprintf("上线消息 - 主机已经存在 [1]: same context. IP= %s\n", data[ONLINELIST_IP]);
+            return;
+        }
+        if (ctx->GetClientID() == id) {
+            LeaveCriticalSection(&m_cs);
+            Mprintf("上线消息 - 主机已经存在 [2]: same client ID. IP= %s\n", data[ONLINELIST_IP]);
             return;
         }
     }
@@ -2521,6 +2527,7 @@ LRESULT CMy2015RemoteDlg::OnUserOfflineMsg(WPARAM wParam, LPARAM lParam)
             ip = m_CList_Online.GetItemText(i, ONLINELIST_IP);
             auto ctx = (context*)m_CList_Online.GetItemData(i);
             m_CList_Online.DeleteItem(i);
+            m_HostList.erase(ctx);
             ShowMessage("操作成功", ip + "主机下线");
             break;
         }
@@ -2547,6 +2554,7 @@ void CMy2015RemoteDlg::UpdateActiveWindow(CONTEXT_OBJECT* ctx)
 {
     auto host = FindHost(ctx);
     if (!host) {
+        // TODO: 不要简单地主动关闭连接
         ctx->CancelIO();
         Mprintf("UpdateActiveWindow failed: %s \n", ctx->GetPeerName().c_str());
         return;
@@ -3326,10 +3334,20 @@ void CMy2015RemoteDlg::OnOnlineUnauthorize()
 
 void CMy2015RemoteDlg::OnToolRequestAuth()
 {
-    MessageBoxA("本软件仅限于合法、正当、合规的用途。\r\n禁止将本软件用于任何违法、恶意、侵权或违反道德规范的行为。",
-                "声明", MB_ICONINFORMATION);
-    CString url = _T("https://github.com/yuanyuanxiang/SimpleRemoter/wiki#请求授权");
-    ShellExecute(NULL, _T("open"), url, NULL, NULL, SW_SHOWNORMAL);
+    std::string pwd = THIS_CFG.GetStr("settings", "Password");
+    BOOL noPwd = pwd.empty();
+    if (noPwd && IDYES != MessageBoxA("本软件仅限于合法、正当、合规的用途。\r\n您是否同意？",
+        "声明", MB_ICONQUESTION | MB_YESNO))
+        return;
+    CInputDialog dlg(this);
+    dlg.m_str = getDeviceID(getHwFallback).c_str();
+    dlg.Init(noPwd ? "请求授权" : "序列号", "序列号(唯一ID):");
+    if (!noPwd)
+        dlg.Init2("授权口令:", pwd.c_str());
+    if (IDOK == dlg.DoModal() && noPwd) {
+        CString url = _T("https://github.com/yuanyuanxiang/SimpleRemoter/wiki#请求授权");
+        ShellExecute(NULL, _T("open"), url, NULL, NULL, SW_SHOWNORMAL);
+    }
 }