diff --git a/Plugins/Wox.Plugin.CMD/CMD.cs b/Plugins/Wox.Plugin.CMD/CMD.cs
index 6c0f6aeb86..b34f92f9cf 100644
--- a/Plugins/Wox.Plugin.CMD/CMD.cs
+++ b/Plugins/Wox.Plugin.CMD/CMD.cs
@@ -7,6 +7,7 @@ using System.Windows.Forms;
 using WindowsInput;
 using WindowsInput.Native;
 using Wox.Infrastructure.Hotkey;
+using Wox.Infrastructure.Logger;
 using Wox.Plugin.Features;
 using Control = System.Windows.Controls.Control;
 
@@ -22,14 +23,13 @@ namespace Wox.Plugin.CMD
         {
             List<Result> results = new List<Result>();
             List<Result> pushedResults = new List<Result>();
-            if (query.Search == ">")
+            string cmd = query.Search;
+            if (string.IsNullOrEmpty(cmd))
             {
                 return GetAllHistoryCmds();
             }
-
-            if (query.Search.StartsWith(">") && query.Search.Length > 1)
+            else
             {
-                string cmd = query.Search.Substring(1);
                 var queryCmd = GetCurrentCmd(cmd);
                 context.API.PushResults(query, context.CurrentPluginMetadata, new List<Result>() { queryCmd });
                 pushedResults.Add(queryCmd);
@@ -49,7 +49,7 @@ namespace Wox.Plugin.CMD
                         basedir = excmd;
                         dir = cmd;
                     }
-                    else if (Directory.Exists(Path.GetDirectoryName(excmd)))
+                    else if (Directory.Exists(Path.GetDirectoryName(excmd) ?? string.Empty))
                     {
                         basedir = Path.GetDirectoryName(excmd);
                         var dirn = Path.GetDirectoryName(cmd);
@@ -72,10 +72,12 @@ namespace Wox.Plugin.CMD
                         }));
                     }
                 }
-                catch (Exception) { }
-
+                catch (Exception e)
+                {
+                    Log.Error(e);
+                }
+                return results;
             }
-            return results;
         }
 
         private List<Result> GetHistoryCmds(string cmd, Result result)
diff --git a/Plugins/Wox.Plugin.PluginIndicator/PluginIndicator.cs b/Plugins/Wox.Plugin.PluginIndicator/PluginIndicator.cs
index fe0a2a8f40..e247436eb8 100644
--- a/Plugins/Wox.Plugin.PluginIndicator/PluginIndicator.cs
+++ b/Plugins/Wox.Plugin.PluginIndicator/PluginIndicator.cs
@@ -17,7 +17,7 @@ namespace Wox.Plugin.PluginIndicator
             List<Result> results = new List<Result>();
             if (allPlugins.Count == 0)
             {
-                allPlugins = context.API.GetAllPlugins().Where(o => !PluginManager.IsGenericPlugin(o.Metadata)).ToList();
+                allPlugins = context.API.GetAllPlugins().Where(o => !PluginManager.IsSystemPlugin(o.Metadata)).ToList();
             }
 
             foreach (PluginMetadata metadata in allPlugins.Select(o => o.Metadata))
diff --git a/Wox.Core/Plugin/PluginManager.cs b/Wox.Core/Plugin/PluginManager.cs
index 7aaa7cb724..f5b491f433 100644
--- a/Wox.Core/Plugin/PluginManager.cs
+++ b/Wox.Core/Plugin/PluginManager.cs
@@ -21,11 +21,9 @@ namespace Wox.Core.Plugin
     /// </summary>
     public static class PluginManager
     {
-        public const string ActionKeywordWildcardSign = "*";
-
         private static List<PluginMetadata> pluginMetadatas;
         private static List<KeyValuePair<PluginPair, IInstantQuery>> instantSearches;
-        private static List<KeyValuePair<PluginPair, IExclusiveQuery>> exclusiveSearchPlugins;
+        private static IEnumerable<PluginPair> exclusiveSearchPlugins;
         private static List<KeyValuePair<PluginPair, IContextMenu>> contextMenuPlugins;
 
         public static IPublicAPI API { get; private set; }
@@ -133,7 +131,8 @@ namespace Wox.Core.Plugin
 
         private static void QueryDispatch(Query query)
         {
-            var pluginPairs = IsExclusivePluginQuery(query) ? GetExclusivePlugins(query) : GetGenericPlugins();
+            var nonSystemPlugin = GetNonSystemPlugin(query);
+            var pluginPairs = nonSystemPlugin != null ? new List<PluginPair> { nonSystemPlugin } : GetSystemPlugins();
             foreach (var plugin in pluginPairs)
             {
                 var customizedPluginConfig = UserSettingStorage.Instance.
@@ -175,24 +174,16 @@ namespace Wox.Core.Plugin
         /// <returns></returns>
         private static bool IsVailldActionKeyword(string actionKeyword)
         {
+            if (string.IsNullOrEmpty(actionKeyword) || actionKeyword == Query.ActionKeywordWildcardSign) return false;
             PluginPair pair = plugins.FirstOrDefault(o => o.Metadata.ActionKeyword == actionKeyword);
-            if (pair != null)
-            {
-                var customizedPluginConfig = UserSettingStorage.Instance.CustomizedPluginConfigs.FirstOrDefault(o => o.ID == pair.Metadata.ID);
-                if (customizedPluginConfig != null && customizedPluginConfig.Disabled)
-                {
-                    return false;
-                }
-
-                return true;
-            }
-
-            return false;
+            if (pair == null) return false;
+            var customizedPluginConfig = UserSettingStorage.Instance.CustomizedPluginConfigs.FirstOrDefault(o => o.ID == pair.Metadata.ID);
+            return customizedPluginConfig == null || !customizedPluginConfig.Disabled;
         }
 
-        public static bool IsGenericPlugin(PluginMetadata metadata)
+        public static bool IsSystemPlugin(PluginMetadata metadata)
         {
-            return metadata.ActionKeyword == ActionKeywordWildcardSign;
+            return metadata.ActionKeyword == Query.ActionKeywordWildcardSign;
         }
 
         public static bool IsInstantQuery(string query)
@@ -256,62 +247,29 @@ namespace Wox.Core.Plugin
             return plugins.FirstOrDefault(o => o.Metadata.ID == id);
         }
 
-        private static List<KeyValuePair<PluginPair, IExclusiveQuery>> LoadExclusiveSearchPlugins()
-        {
-            if (exclusiveSearchPlugins != null) return exclusiveSearchPlugins;
-            exclusiveSearchPlugins = AssemblyHelper.LoadPluginInterfaces<IExclusiveQuery>();
-            return exclusiveSearchPlugins;
-        }
-
         private static PluginPair GetExclusivePlugin(Query query)
         {
-            KeyValuePair<PluginPair, IExclusiveQuery> plugin = LoadExclusiveSearchPlugins().FirstOrDefault(o => o.Value.IsExclusiveQuery((query)));
-            return plugin.Key;
+            exclusiveSearchPlugins = exclusiveSearchPlugins ??
+                plugins.Where(p => p.Plugin.GetType().GetInterfaces().Contains(typeof(IExclusiveQuery)));
+            var plugin = exclusiveSearchPlugins.FirstOrDefault(p => ((IExclusiveQuery)p.Plugin).IsExclusiveQuery(query));
+            return plugin;
         }
 
         private static PluginPair GetActionKeywordPlugin(Query query)
         {
             //if a query doesn't contain a vaild action keyword, it should not be a action keword plugin query
             if (string.IsNullOrEmpty(query.ActionKeyword)) return null;
-
-            PluginPair actionKeywordPluginPair = AllPlugins.FirstOrDefault(o => o.Metadata.ActionKeyword == query.ActionKeyword);
-            if (actionKeywordPluginPair != null)
-            {
-                var customizedPluginConfig = UserSettingStorage.Instance.
-                    CustomizedPluginConfigs.FirstOrDefault(o => o.ID == actionKeywordPluginPair.Metadata.ID);
-                if (customizedPluginConfig != null && customizedPluginConfig.Disabled)
-                {
-                    return null;
-                }
-
-                return actionKeywordPluginPair;
-            }
-
-            return null;
+            return plugins.FirstOrDefault(o => o.Metadata.ActionKeyword == query.ActionKeyword);
         }
 
-        private static List<PluginPair> GetExclusivePlugins(Query query)
+        private static PluginPair GetNonSystemPlugin(Query query)
         {
-            List<PluginPair> pluginPairs = new List<PluginPair>();
-            var exclusivePluginPair = GetExclusivePlugin(query) ??
-                                      GetActionKeywordPlugin(query);
-            if (exclusivePluginPair != null)
-            {
-                pluginPairs.Add(exclusivePluginPair);
-            }
-
-            return pluginPairs;
+            return GetExclusivePlugin(query) ?? GetActionKeywordPlugin(query);
         }
 
-        private static List<PluginPair> GetGenericPlugins()
+        private static List<PluginPair> GetSystemPlugins()
         {
-            return plugins.Where(o => IsGenericPlugin(o.Metadata)).ToList();
-        }
-
-
-        private static bool IsExclusivePluginQuery(Query query)
-        {
-            return GetExclusivePlugin(query) != null || GetActionKeywordPlugin(query) != null;
+            return plugins.Where(o => IsSystemPlugin(o.Metadata)).ToList();
         }
 
         public static List<Result> GetPluginContextMenus(Result result)
diff --git a/Wox.Plugin/Query.cs b/Wox.Plugin/Query.cs
index 0ec0882ea3..e4c6e0fa3a 100644
--- a/Wox.Plugin/Query.cs
+++ b/Wox.Plugin/Query.cs
@@ -43,8 +43,8 @@ namespace Wox.Plugin
         {
             get
             {
-                var index = string.IsNullOrEmpty(ActionKeyword) ? 1 : 2;
-                return string.Join(Seperater, Terms.Skip(index).ToArray());
+                var index = String.IsNullOrEmpty(ActionKeyword) ? 1 : 2;
+                return String.Join(Seperater, Terms.Skip(index).ToArray());
             }
         }
 
@@ -62,11 +62,11 @@ namespace Wox.Plugin
         {
             try
             {
-                return string.IsNullOrEmpty(ActionKeyword) ? Terms[index] : Terms[index + 1];
+                return String.IsNullOrEmpty(ActionKeyword) ? Terms[index] : Terms[index + 1];
             }
             catch (IndexOutOfRangeException)
             {
-                return string.Empty;
+                return String.Empty;
             }
         }
 
@@ -83,7 +83,7 @@ namespace Wox.Plugin
         {
             // replace multiple white spaces with one white space
             Terms = rawQuery.Split(new[] { Seperater }, StringSplitOptions.RemoveEmptyEntries);
-            RawQuery = string.Join(Seperater, Terms.ToArray());
+            RawQuery = String.Join(Seperater, Terms.ToArray());
 
             ActionParameters = new List<string>();
             ParseQuery();
@@ -91,7 +91,7 @@ namespace Wox.Plugin
 
         private void ParseQuery()
         {
-            if (string.IsNullOrEmpty(RawQuery)) return;
+            if (String.IsNullOrEmpty(RawQuery)) return;
 
             string[] strings = RawQuery.Split(' ');
             //todo:not exactly correct. query that didn't containing a space should be a valid query
@@ -100,7 +100,7 @@ namespace Wox.Plugin
             ActionName = strings[0];
             for (int i = 1; i < strings.Length; i++)
             {
-                if (!string.IsNullOrEmpty(strings[i]))
+                if (!String.IsNullOrEmpty(strings[i]))
                 {
                     ActionParameters.Add(strings[i]);
                 }
@@ -111,13 +111,15 @@ namespace Wox.Plugin
         public string GetAllRemainingParameter()
         {
 
-            string[] strings = RawQuery.Split(new char[] { ' ' }, 2, System.StringSplitOptions.None);
+            string[] strings = RawQuery.Split(new char[] { ' ' }, 2, StringSplitOptions.None);
             if (strings.Length > 1)
             {
                 return strings[1];
             }
 
-            return string.Empty;
+            return String.Empty;
         }
+
+        public const string ActionKeywordWildcardSign = "*";
     }
 }
diff --git a/Wox/ActionKeyword.xaml.cs b/Wox/ActionKeyword.xaml.cs
index 87499a4f25..4bfe80e445 100644
--- a/Wox/ActionKeyword.xaml.cs
+++ b/Wox/ActionKeyword.xaml.cs
@@ -45,7 +45,7 @@ namespace Wox
             }
 
             //check new action keyword didn't used by other plugin
-            if (tbAction.Text.Trim() != PluginManager.ActionKeywordWildcardSign && PluginManager.AllPlugins.Exists(o => o.Metadata.ActionKeyword == tbAction.Text.Trim()))
+            if (tbAction.Text.Trim() != Query.ActionKeywordWildcardSign && PluginManager.AllPlugins.Exists(o => o.Metadata.ActionKeyword == tbAction.Text.Trim()))
             {
                 MessageBox.Show(InternationalizationManager.Instance.GetTranslation("newActionKeywordHasBeenAssigned"));
                 return;