diff --git a/src/Orchard.Web/Modules/Orchard.MultiTenancy/Module.txt b/src/Orchard.Web/Modules/Orchard.MultiTenancy/Module.txt
index e45f659b3..e3f4a84f6 100644
--- a/src/Orchard.Web/Modules/Orchard.MultiTenancy/Module.txt
+++ b/src/Orchard.Web/Modules/Orchard.MultiTenancy/Module.txt
@@ -1,4 +1,4 @@
-Name: MultiTenancy
+Name: Multi Tenancy
 AntiForgery: enabled
 Author: The Orchard Team
 Website: http://orchardproject.net
diff --git a/src/Orchard.Web/Modules/Upgrade/Controllers/MediaController.cs b/src/Orchard.Web/Modules/Upgrade/Controllers/MediaController.cs
index 9bcd256da..dadf0e029 100644
--- a/src/Orchard.Web/Modules/Upgrade/Controllers/MediaController.cs
+++ b/src/Orchard.Web/Modules/Upgrade/Controllers/MediaController.cs
@@ -1,9 +1,11 @@
 using System;
 using System.Collections.Generic;
+using System.IO;
 using System.Linq;
 using System.Web.Mvc;
 using Orchard;
 using Orchard.Environment.Features;
+using Orchard.FileSystems.Media;
 using Orchard.Localization;
 using Orchard.Logging;
 using Orchard.MediaLibrary.Models;
@@ -18,15 +20,19 @@ namespace Upgrade.Controllers {
         private readonly IOrchardServices _orchardServices;
         private readonly IFeatureManager _featureManager;
         private readonly IEnumerable<IMediaLibraryService> _mediaLibraryServices;
-        private IMediaLibraryService _mediaLibraryService { get { return _mediaLibraryServices.FirstOrDefault(); }} 
+        private readonly IMimeTypeProvider _mimeTypeProvider;
+        private IMediaLibraryService _mediaLibraryService { get { return _mediaLibraryServices.FirstOrDefault(); }}
+        private int BATCH = 100;
 
         public MediaController(
             IOrchardServices orchardServices,
             IFeatureManager featureManager,
-            IEnumerable<IMediaLibraryService> mediaLibraryServices) {
+            IEnumerable<IMediaLibraryService> mediaLibraryServices,
+            IMimeTypeProvider mimeTypeProvider) {
             _orchardServices = orchardServices;
             _featureManager = featureManager;
             _mediaLibraryServices = mediaLibraryServices;
+            _mimeTypeProvider = mimeTypeProvider;
 
             Logger = NullLogger.Instance;
         }
@@ -41,6 +47,26 @@ namespace Upgrade.Controllers {
             }
             else {
                 ViewBag.CanMigrate = true;
+
+                var extensions = new HashSet<string>();
+
+                // crawl media file for all file extensions
+                _mediaLibraryService.GetMediaFolders(null).ToList()
+                    .ForEach(mediaFolder => ImportMediaFolder(mediaFolder, x => {
+                        if (!String.IsNullOrWhiteSpace(x.MediaPath)) {
+                            var extension = Path.GetExtension(x.MediaPath);
+                            if (!String.IsNullOrWhiteSpace(extension)) {
+                                extensions.Add(extension);
+                            }
+                        }
+                    }));
+
+                foreach (var extension in extensions) {
+                    if (_mimeTypeProvider.GetMimeType("." + extension) == "application/unknown") {
+                        _orchardServices.Notifier.Warning(T("Unknown MIME type: {0}", extension));
+                        ViewBag.CanMigrate = false;
+                    }
+                }
             }
 
             return View();
@@ -51,46 +77,68 @@ namespace Upgrade.Controllers {
             if (!_orchardServices.Authorizer.Authorize(StandardPermissions.SiteOwner, T("Not allowed to convert media files.")))
                 return new HttpUnauthorizedResult();
 
+            var count = 0;
+            var hasMore = false;
+
             // crawl media file, ignore recipes and profiles
             IEnumerable<MediaFolder> mediaFolders = _mediaLibraryService.GetMediaFolders(null);
             foreach (var mediaFolder in mediaFolders) {
-                ImportMediaFolder(mediaFolder);
+                ImportMediaFolder(mediaFolder, x => {
+                    if (count < BATCH) {
+                        if (ImportMediaFile(x) != null) {
+                            count++;
+                        }
+                    }
+                    else {
+                        hasMore = true;
+                    }
+                });
+            }
+
+            if (count > 0) {
+                _orchardServices.Notifier.Information(T("{0} media files were imported.", count));
+            }
+
+            if (hasMore && count <= BATCH) {
+                _orchardServices.Notifier.Information(T("More than {0} media files were found, please import again.", BATCH));
+            }
+            else {
+                _orchardServices.Notifier.Information(T("All media files were imported."));
             }
 
-            _orchardServices.Notifier.Information(T("Media files were migrated successfully."));
-            
             return RedirectToAction("Index");
         }
 
-        private void ImportMediaFolder(MediaFolder mediaFolder) {
+        private void ImportMediaFolder(MediaFolder mediaFolder, Action<MediaFile> action) {
             foreach (var mediaFile in _mediaLibraryService.GetMediaFiles(mediaFolder.MediaPath)) {
-                ImportMediaFile(mediaFile);
+                action(mediaFile);
             }
 
             // recursive call on sub-folders
             foreach (var subMediaFolder in _mediaLibraryService.GetMediaFolders(mediaFolder.MediaPath)) {
-                ImportMediaFolder(subMediaFolder);
+                ImportMediaFolder(subMediaFolder, action);
             }
         }
 
-        private void ImportMediaFile(MediaFile mediaFile) {
+        private MediaPart ImportMediaFile(MediaFile mediaFile) {
             // foreach media file, if there is no media with the same url, import it
 
             var contentManager = _orchardServices.ContentManager;
             var media = contentManager.Query().ForPart<MediaPart>().Where<MediaPartRecord>(x => x.FolderPath == mediaFile.FolderName && x.FileName == mediaFile.Name).Slice(0, 1).FirstOrDefault();
 
             if (media != null) {
-                _orchardServices.Notifier.Warning(T("Media {0} has already been imported.", mediaFile.MediaPath));
-                return;
+                // _orchardServices.Notifier.Warning(T("Media {0} has already been imported.", mediaFile.MediaPath));
+                return null;
             }
             
             try {
-                _orchardServices.Notifier.Information(T("Importing {0}.", mediaFile.MediaPath));
-                _mediaLibraryService.ImportMedia(mediaFile.FolderName, mediaFile.Name);
+                //_orchardServices.Notifier.Information(T("Importing {0}.", mediaFile.MediaPath));
+                return _mediaLibraryService.ImportMedia(mediaFile.FolderName, mediaFile.Name);
             }
             catch(Exception e) {
                 _orchardServices.Notifier.Error(T("Error while importing {0}. Please check the logs", mediaFile.MediaPath));
                 Logger.Error(e, "Error while importing {0}", mediaFile.MediaPath);
+                return null;
             }
         }
     }
diff --git a/src/Orchard.Web/Modules/Upgrade/Views/Media/Index.cshtml b/src/Orchard.Web/Modules/Upgrade/Views/Media/Index.cshtml
index 94d630cba..2ccdfc02b 100644
--- a/src/Orchard.Web/Modules/Upgrade/Views/Media/Index.cshtml
+++ b/src/Orchard.Web/Modules/Upgrade/Views/Media/Index.cshtml
@@ -7,6 +7,9 @@
     <fieldset>
         <legend>@T("Migrating Media Files:")</legend>
         <span class="hint">@T("This migration step will create and organize new Media Content Items based on the media files in your ~/Media folder.")</span>
+        @if (ViewBag.CanMigrate) {
+            <span class="hint">@T("Before importing, please ensure the server has the expected mime types already registered as explained here: <a href=\"http://www.iis.net/configreference/system.webserver/staticcontent/mimemap\">http://www.iis.net/configreference/system.webserver/staticcontent/mimemap</a>")</span>
+        }
     </fieldset>
     <fieldset>
         @if (ViewBag.CanMigrate) {