diff --git a/src/modules/launcher/Plugins/Wox.Plugin.Indexer/Main.cs b/src/modules/launcher/Plugins/Wox.Plugin.Indexer/Main.cs
index 8d6af797e9..b547815e76 100644
--- a/src/modules/launcher/Plugins/Wox.Plugin.Indexer/Main.cs
+++ b/src/modules/launcher/Plugins/Wox.Plugin.Indexer/Main.cs
@@ -87,11 +87,15 @@ namespace Wox.Plugin.Indexer
                         results.Add(r);
                     }
                 }
+                catch(InvalidOperationException)
+                {
+                    //The connection has closed, internal error of ExecuteReader()
+                    //Not showing this exception to the users
+                }
                 catch (Exception ex)
                 {
                     results.Add(new Result
                     {
-                        // TODO: Localize the string
                         Title = ex.ToString(),
                         IcoPath = "Images\\WindowsIndexerImg.bmp"
                     });
diff --git a/src/modules/launcher/Plugins/Wox.Plugin.Indexer/SearchHelper/WindowsSearchAPI.cs b/src/modules/launcher/Plugins/Wox.Plugin.Indexer/SearchHelper/WindowsSearchAPI.cs
index 84f81b1a95..863a717925 100644
--- a/src/modules/launcher/Plugins/Wox.Plugin.Indexer/SearchHelper/WindowsSearchAPI.cs
+++ b/src/modules/launcher/Plugins/Wox.Plugin.Indexer/SearchHelper/WindowsSearchAPI.cs
@@ -10,9 +10,12 @@ namespace Wox.Plugin.Indexer.SearchHelper
         public OleDbConnection conn;
         public OleDbCommand command;
         public OleDbDataReader WDSResults;
+        private readonly object _lock = new object();
+        
 
-        public IEnumerable<SearchResult> ExecuteQuery(ISearchQueryHelper queryHelper, string keyword)
+        public List<SearchResult> ExecuteQuery(ISearchQueryHelper queryHelper, string keyword)
         {
+            List<SearchResult> _Result = new List<SearchResult>();
             // Generate SQL from our parameters, converting the userQuery from AQS->WHERE clause
             string sqlQuery = queryHelper.GenerateSQLFromUserQuery(keyword);
 
@@ -34,12 +37,14 @@ namespace Wox.Plugin.Indexer.SearchHelper
                             while (WDSResults.Read() && WDSResults.GetValue(0) != DBNull.Value)
                             {
                                 var result = new SearchResult { Path = WDSResults.GetString(0) };
-                                yield return result;
+                                _Result.Add(result);
                             }
                         }
                     }
                 }
             }
+
+            return _Result;
         }
 
 
@@ -90,10 +95,12 @@ namespace Wox.Plugin.Indexer.SearchHelper
         [STAThread]
         public IEnumerable<SearchResult> Search(string keyword, string pattern = "*", int maxCount = 100)
         {
-            ISearchQueryHelper queryHelper;
-            InitQueryHelper(out queryHelper, maxCount);
-            ModifyQueryHelper(ref queryHelper, pattern);
-            return ExecuteQuery(queryHelper, keyword);
+            lock(_lock){
+                ISearchQueryHelper queryHelper;
+                InitQueryHelper(out queryHelper, maxCount);
+                ModifyQueryHelper(ref queryHelper, pattern);
+                return ExecuteQuery(queryHelper, keyword);
+            }
         }
     }
 }