diff --git a/src/Umbraco.Web.UI.Client/src/common/resources/package.resource.js b/src/Umbraco.Web.UI.Client/src/common/resources/package.resource.js
index bfb801e536..9dae2008e2 100644
--- a/src/Umbraco.Web.UI.Client/src/common/resources/package.resource.js
+++ b/src/Umbraco.Web.UI.Client/src/common/resources/package.resource.js
@@ -24,6 +24,15 @@ function packageResource($q, $http, umbDataFormatter, umbRequestHelper) {
                'Failed to get installed packages');
         },
 
+        validateInstalled: function (name, version) {
+            return umbRequestHelper.resourcePromise(
+               $http.post(
+                   umbRequestHelper.getApiUrl(
+                       "packageInstallApiBaseUrl",
+                       "ValidateInstalled", { name: name, version: version })),
+               'Failed to validate package ' + name);
+        },
+
         deleteCreatedPackage: function (packageId) {
             return umbRequestHelper.resourcePromise(
                $http.post(
diff --git a/src/Umbraco.Web.UI.Client/src/views/dashboard/dashboard.tabs.controller.js b/src/Umbraco.Web.UI.Client/src/views/dashboard/dashboard.tabs.controller.js
index 42ceb86964..53c0e0419d 100644
--- a/src/Umbraco.Web.UI.Client/src/views/dashboard/dashboard.tabs.controller.js
+++ b/src/Umbraco.Web.UI.Client/src/views/dashboard/dashboard.tabs.controller.js
@@ -17,28 +17,28 @@ function startUpVideosDashboardController($scope, xmlhelper, $log, $http) {
 angular.module("umbraco").controller("Umbraco.Dashboard.StartupVideosController", startUpVideosDashboardController);
 
 
-function FormsController($scope, $route, $cookieStore, packageResource) {
+function FormsController($scope, $route, $cookieStore, packageResource, localizationService) {
     $scope.installForms = function(){
-        $scope.state = "Installng package";
+        $scope.state = localizationService.localize("packager_installStateDownloading");
         packageResource
             .fetch("CD44CF39-3D71-4C19-B6EE-948E1FAF0525")
             .then(function(pack) {
-                    $scope.state = "importing";
+                $scope.state = localizationService.localize("packager_installStateImporting");
                     return packageResource.import(pack);
                 },
                 $scope.error)
             .then(function(pack) {
-                    $scope.state = "Installing";
+                $scope.state = localizationService.localize("packager_installStateInstalling");
                     return packageResource.installFiles(pack);
                 },
                 $scope.error)
             .then(function(pack) {
-                    $scope.state = "Restarting, please wait...";
+                $scope.state = localizationService.localize("packager_installStateRestarting");
                     return packageResource.installData(pack);
                 },
                 $scope.error)
             .then(function(pack) {
-                    $scope.state = "All done, your browser will now refresh";
+                $scope.state = localizationService.localize("packager_installStateComplete");
                     return packageResource.cleanUp(pack);
                 },
                 $scope.error)
diff --git a/src/Umbraco.Web.UI.Client/src/views/packager/views/install-local.controller.js b/src/Umbraco.Web.UI.Client/src/views/packager/views/install-local.controller.js
index 63a270386d..0f3455203d 100644
--- a/src/Umbraco.Web.UI.Client/src/views/packager/views/install-local.controller.js
+++ b/src/Umbraco.Web.UI.Client/src/views/packager/views/install-local.controller.js
@@ -1,7 +1,7 @@
 (function () {
     "use strict";
 
-    function PackagesInstallLocalController($scope, $route, $location, Upload, umbRequestHelper, packageResource, localStorageService, $timeout, $window) {
+    function PackagesInstallLocalController($scope, $route, $location, Upload, umbRequestHelper, packageResource, localStorageService, $timeout, $window, localizationService) {
 
         var vm = this;
         vm.state = "upload";
@@ -9,7 +9,8 @@
         vm.localPackage = {};
         vm.installPackage = installPackage;
         vm.installState = {
-            status: ""
+            status: "",
+            progress:0
         };
         vm.zipFile = {
             uploadStatus: "idle",
@@ -98,7 +99,7 @@
         }
 
         function installPackage() {
-            vm.installState.status = "Importing";
+            vm.installState.status = localizationService.localize("packager_installStateImporting");
             vm.installState.progress = "0";
 
             //TODO: If any of these fail, will they keep calling the next one?
@@ -106,19 +107,19 @@
                 .import(vm.localPackage)                
                 .then(function(pack) {
                         vm.installState.progress = "25";
-                        vm.installState.status = "Installing...";
+                        vm.installState.status = localizationService.localize("packager_installStateInstalling");
                         vm.installState.progress = "50";
                         return packageResource.installFiles(pack);
                     },
                     installError)
                 .then(function(pack) {
-                        vm.installState.status = "Restarting, please wait...";
+                    vm.installState.status = localizationService.localize("packager_installStateRestarting");
                         vm.installState.progress = "75";
                         return packageResource.installData(pack);
                     },
                     installError)
                 .then(function(pack) {
-                        vm.installState.status = "All done, your browser will now refresh, please wait...";
+                    vm.installState.status = localizationService.localize("packager_installStateComplete");
                         vm.installState.progress = "100";
                         return packageResource.cleanUp(pack);
                     },
diff --git a/src/Umbraco.Web.UI.Client/src/views/packager/views/installed.controller.js b/src/Umbraco.Web.UI.Client/src/views/packager/views/installed.controller.js
index a1bc40ece0..ce1d2cca0f 100644
--- a/src/Umbraco.Web.UI.Client/src/views/packager/views/installed.controller.js
+++ b/src/Umbraco.Web.UI.Client/src/views/packager/views/installed.controller.js
@@ -1,7 +1,7 @@
 (function () {
     "use strict";
 
-    function PackagesInstalledController($scope, $route, $location, packageResource, $timeout, $window, localStorageService) {
+    function PackagesInstalledController($scope, $route, $location, packageResource, $timeout, $window, localStorageService, localizationService) {
 
         var vm = this;
 
@@ -28,14 +28,14 @@
         }
 
         function uninstallPackage(installedPackage) {
-            vm.installState.status = "Uninstalling package...";
+            vm.installState.status = localizationService.localize("packager_installStateUninstalling");
             vm.installState.progress = "0";
 
             packageResource.uninstall(installedPackage.id)
                 .then(function () {
 
                     if (installedPackage.files.length > 0) {
-                        vm.installState.status = "All done, your browser will now refresh";
+                        vm.installState.status = localizationService.localize("packager_installStateComplete");
                         vm.installState.progress = "100";
 
                         //set this flag so that on refresh it shows the installed packages list
diff --git a/src/Umbraco.Web.UI.Client/src/views/packager/views/repo.controller.js b/src/Umbraco.Web.UI.Client/src/views/packager/views/repo.controller.js
index 6aae118085..dc6dfe7da4 100644
--- a/src/Umbraco.Web.UI.Client/src/views/packager/views/repo.controller.js
+++ b/src/Umbraco.Web.UI.Client/src/views/packager/views/repo.controller.js
@@ -1,7 +1,7 @@
 (function () {
     "use strict";
 
-    function PackagesRepoController($scope, $route, $location, $timeout, ourPackageRepositoryResource, $q, packageResource, localStorageService) {
+    function PackagesRepoController($scope, $route, $location, $timeout, ourPackageRepositoryResource, $q, packageResource, localStorageService, localizationService) {
 
         var vm = this;
 
@@ -15,7 +15,9 @@
         };
         vm.searchQuery = "";
         vm.installState = {
-            status: ""
+            status: "",
+            progress: 0,
+            type: "ok"
         };
         vm.selectCategory = selectCategory;
         vm.showPackageDetails = showPackageDetails;
@@ -107,11 +109,20 @@
 
         function showPackageDetails(selectedPackage) {
             ourPackageRepositoryResource.getDetails(selectedPackage.id)
-                .then(function(pack) {
-                    vm.package = pack;
-                    vm.packageViewState = "packageDetails";
+                .then(function (pack) {
+                    packageResource.validateInstalled(pack.name, pack.latestVersion)
+                        .then(function() {
+                            //ok, can install
+                            vm.package = pack;
+                            vm.package.isValid = true;
+                            vm.packageViewState = "packageDetails";
+                        }, function() {
+                            //nope, cannot install
+                            vm.package = pack;
+                            vm.package.isValid = false;
+                            vm.packageViewState = "packageDetails";
+                        })
                 });
-
         }
 
         function setPackageViewState(state) {
@@ -154,35 +165,42 @@
                         vm.loading = false;
                         vm.localPackage = pack;
                         vm.localPackage.allowed = true;
-                    },
-                    error);
+                }, function (evt, status, headers, config) {
+                    
+                    if (status == 400) {
+                        //it's a validation error
+                        vm.installState.type = "error";
+                        vm.zipFile.serverErrorMessage = evt.message;
+                    }
+                });
         }
 
         function error(e, args) {
-
+            //This will return a rejection meaning that the promise change above will stop
+            return $q.reject();
         }
 
         function installPackage(selectedPackage) {
 
-            vm.installState.status = "importing...";
+            vm.installState.status = localizationService.localize("packager_installStateImporting");
             vm.installState.progress = "0";
 
             packageResource
                 .import(selectedPackage)
                 .then(function(pack) {
-                        vm.installState.status = "Installing...";
+                        vm.installState.status = localizationService.localize("packager_installStateInstalling");
                         vm.installState.progress = "33";
                         return packageResource.installFiles(pack);
                     },
                     error)
                 .then(function(pack) {
-                        vm.installState.status = "Restarting, please wait...";
+                        vm.installState.status = localizationService.localize("packager_installStateRestarting");
                         vm.installState.progress = "66";
                         return packageResource.installData(pack);
                     },
                     error)
                 .then(function(pack) {
-                        vm.installState.status = "All done, your browser will now refresh";
+                        vm.installState.status = localizationService.localize("packager_installStateComplete");
                         vm.installState.progress = "100";
                         return packageResource.cleanUp(pack);
                     },
diff --git a/src/Umbraco.Web.UI.Client/src/views/packager/views/repo.html b/src/Umbraco.Web.UI.Client/src/views/packager/views/repo.html
index a78966e492..973fa8c440 100644
--- a/src/Umbraco.Web.UI.Client/src/views/packager/views/repo.html
+++ b/src/Umbraco.Web.UI.Client/src/views/packager/views/repo.html
@@ -153,7 +153,12 @@
                 <div class="umb-package-details__sidebar">
 
                     <div class="umb-package-details__section">
-                        <button class="umb-era-button -blue -full-width" ng-click="vm.downloadPackage(vm.package)">Install package</button>
+                        <button class="umb-era-button -blue -full-width" 
+                                ng-if="vm.package.isValid === true"
+                                ng-click="vm.downloadPackage(vm.package)">Install package</button>
+                        <div class="umb-info-local-item text-error" ng-if="vm.package.isValid === false">
+                            <localize key="packager_packageAlreadyInstalled">The package and version chosen is already installed</localize>
+                        </div>
                     </div>
 
                     <div class="umb-package-details__section">
@@ -310,6 +315,7 @@
                                     <strong class="label-text">I accept <a href="{{ vm.localPackage.licenseUrl }}">terms of use</a></strong>
                                 </label>
                                 <button type="button"
+                                        ng-if="vm.installState.type !== 'error'"
                                         ng-class="{'-inactive' : localPackageForm.$invalid}"
                                         ng-disabled="localPackageForm.$invalid"
                                         class="umb-era-button -blue flex-inline mt3"
@@ -328,8 +334,8 @@
                             <div class="umb-info-local-item text-error" ng-if="!vm.localPackage.isCompatible">
                                 This package cannot be installed, it requires a minimum Umbraco version of {{vm.localPackage.umbracoVersion}}
                             </div>
-
-                            <div class="umb-info-local-item text-info">
+                            
+                            <div class="umb-info-local-item text-info" ng-class="{'text-info' : vm.installState.type !== 'error'}">
                                 <p>{{vm.installState.status}}</p>
                             </div>
 
diff --git a/src/Umbraco.Web.UI/umbraco/config/lang/en.xml b/src/Umbraco.Web.UI/umbraco/config/lang/en.xml
index d9c4bc912e..8012081a1c 100644
--- a/src/Umbraco.Web.UI/umbraco/config/lang/en.xml
+++ b/src/Umbraco.Web.UI/umbraco/config/lang/en.xml
@@ -783,6 +783,13 @@ To manage your website, simply open the Umbraco back office and start adding con
     <key alias="viewPackageWebsite">View package website</key>
     <key alias="packageAlreadyInstalled">The package and version chosen is already installed</key>
     <key alias="targetVersionMismatch">This package cannot be installed, it requires a minimum Umbraco version of %0%</key>
+    <key alias="installStateUninstalling">Uninstalling...</key>
+    <key alias="installStateDownloading">Downloading...</key>
+    <key alias="installStateImporting">Importing...</key>
+    <key alias="installStateInstalling">Installing...</key>
+    <key alias="installStateRestarting">Restarting, please wait...</key>
+    <key alias="installStateComplete">All done, your browser will now refresh, please wait...</key>
+    
   </area>
   <area alias="paste">
     <key alias="doNothing">Paste with full formatting (Not recommended)</key>
diff --git a/src/Umbraco.Web.UI/umbraco/config/lang/en_us.xml b/src/Umbraco.Web.UI/umbraco/config/lang/en_us.xml
index 8c3f7f8d70..8416efa423 100644
--- a/src/Umbraco.Web.UI/umbraco/config/lang/en_us.xml
+++ b/src/Umbraco.Web.UI/umbraco/config/lang/en_us.xml
@@ -780,6 +780,14 @@ To manage your website, simply open the Umbraco back office and start adding con
     <key alias="packageVersion">Package version</key>
     <key alias="packageVersionHistory">Package version history</key>
     <key alias="viewPackageWebsite">View package website</key>
+    <key alias="packageAlreadyInstalled">The package and version chosen is already installed</key>
+    <key alias="targetVersionMismatch">This package cannot be installed, it requires a minimum Umbraco version of %0%</key>
+    <key alias="installStateUninstalling">Uninstalling...</key>
+    <key alias="installStateDownloading">Downloading...</key>
+    <key alias="installStateImporting">Importing...</key>
+    <key alias="installStateInstalling">Installing...</key>
+    <key alias="installStateRestarting">Restarting, please wait...</key>
+    <key alias="installStateComplete">All done, your browser will now refresh, please wait...</key>
   </area>
   <area alias="paste">
     <key alias="doNothing">Paste with full formatting (Not recommended)</key>
diff --git a/src/Umbraco.Web/Editors/PackageInstallController.cs b/src/Umbraco.Web/Editors/PackageInstallController.cs
index 726584988b..696c8c8e16 100644
--- a/src/Umbraco.Web/Editors/PackageInstallController.cs
+++ b/src/Umbraco.Web/Editors/PackageInstallController.cs
@@ -48,6 +48,21 @@ namespace Umbraco.Web.Editors
     [UmbracoApplicationAuthorize(Core.Constants.Applications.Developer)]
     public class PackageInstallController : UmbracoAuthorizedJsonController
     {
+        /// <summary>
+        /// This checks if this package & version is alraedy installed
+        /// </summary>
+        /// <param name="name"></param>
+        /// <param name="version"></param>
+        /// <returns></returns>
+        [HttpPost]
+        public IHttpActionResult ValidateInstalled(string name, string version)
+        {
+            var validate = ValidateInstalledInternal(name, version);
+            if (validate == false)
+                return BadRequest();
+            return Ok();
+        }
+
         [HttpPost]
         public IHttpActionResult Uninstall(int packageId)
         {
@@ -318,6 +333,34 @@ namespace Umbraco.Web.Editors
             }
         }
 
+        private bool ValidateInstalledInternal(string name, string version)
+        {
+            var allInstalled = InstalledPackage.GetAllInstalledPackages();
+            var found = allInstalled.FirstOrDefault(x =>
+            {
+                if (x.Data.Name != name) return false;
+                //match the exact version
+                if (x.Data.Version == version)
+                {
+                    return true;
+                }
+                //now try to compare the versions
+                Version installed;
+                Version selected;
+                if (Version.TryParse(x.Data.Version, out installed) && Version.TryParse(version, out selected))
+                {
+                    if (installed >= selected) return true;
+                }
+                return false;
+            });
+            if (found != null)
+            {
+                //this package is already installed
+                return false;
+            }
+            return true;
+        }
+
         [HttpPost]
         [FileUploadCleanupFilter(false)]
         public async Task<LocalPackageInstallModel> UploadLocalPackage()
@@ -372,28 +415,11 @@ namespace Umbraco.Web.Editors
                     //Populate the model from the metadata in the package file (zip file)
                     PopulateFromPackageData(model);
 
-                    var allInstalled = InstalledPackage.GetAllInstalledPackages();
-                    var found = allInstalled.FirstOrDefault(x =>
-                    {
-                        if (x.Data.Name != model.Name) return false;
-                        //match the exact version
-                        if (x.Data.Version == model.Version)
-                        {
-                            return true;
-                        }
-                        //now try to compare the versions
-                        Version installed;
-                        Version selected;
-                        if (Version.TryParse(x.Data.Version, out installed) && Version.TryParse(model.Version, out selected))
-                        {
-                            if (installed >= selected) return true;
-                        }
-                        return false;
-                    });
-                    if (found != null)
+                    var validate = ValidateInstalledInternal(model.Name, model.Version);
+                    
+                    if (validate == false)
                     {
                         //this package is already installed
-
                         throw new HttpResponseException(Request.CreateNotificationValidationErrorResponse(
                             Services.TextService.Localize("packager/packageAlreadyInstalled")));                        
                     }
@@ -442,6 +468,15 @@ namespace Umbraco.Web.Editors
             //Populate the model from the metadata in the package file (zip file)
             PopulateFromPackageData(model);
 
+            var validate = ValidateInstalledInternal(model.Name, model.Version);
+
+            if (validate == false)
+            {
+                //this package is already installed
+                throw new HttpResponseException(Request.CreateNotificationValidationErrorResponse(
+                    Services.TextService.Localize("packager/packageAlreadyInstalled")));
+            }
+
             return model;
         }
 
diff --git a/src/Umbraco.Web/umbraco.presentation/umbraco/developer/Packages/installer.aspx.cs b/src/Umbraco.Web/umbraco.presentation/umbraco/developer/Packages/installer.aspx.cs
index 99b054affb..bdcbfaa775 100644
--- a/src/Umbraco.Web/umbraco.presentation/umbraco/developer/Packages/installer.aspx.cs
+++ b/src/Umbraco.Web/umbraco.presentation/umbraco/developer/Packages/installer.aspx.cs
@@ -26,7 +26,8 @@ namespace umbraco.presentation.developer.packages
     /// <summary>
     /// Summary description for packager.
     /// </summary>
-    public partial class Installer : UmbracoEnsuredPage
+    [Obsolete("This should not be used and will be removed in v8, this is kept here only for backwards compat reasons, this page should never be rendered/used")]
+    public class Installer : UmbracoEnsuredPage
     {
         public Installer()
         {