diff --git a/src/umbraco.cms/businesslogic/Packager/Installer.cs b/src/umbraco.cms/businesslogic/Packager/Installer.cs
index 0499157427..6f1ecbf5c7 100644
--- a/src/umbraco.cms/businesslogic/Packager/Installer.cs
+++ b/src/umbraco.cms/businesslogic/Packager/Installer.cs
@@ -5,7 +5,6 @@ using System.Globalization;
 using System.IO;
 using System.Xml;
 using System.Linq;
-using ICSharpCode.SharpZipLib.Zip;
 using Umbraco.Core;
 using Umbraco.Core.Auditing;
 using Umbraco.Core.IO;
@@ -14,6 +13,7 @@ using Umbraco.Core.Packaging;
 using umbraco.cms.businesslogic.web;
 using umbraco.BusinessLogic;
 using System.Diagnostics;
+using System.IO.Compression;
 using umbraco.cms.businesslogic.template;
 using umbraco.interfaces;
 using Umbraco.Core.Events;
@@ -520,7 +520,7 @@ namespace umbraco.cms.businesslogic.packager
         /// <param name="tempDir"></param>
         public void InstallCleanUp(int packageId, string tempDir)
         {
-            
+
             if (Directory.Exists(tempDir))
             {
                 Directory.Delete(tempDir, true);
@@ -751,8 +751,6 @@ namespace umbraco.cms.businesslogic.packager
 
         private static string UnPack(string zipName, bool deleteFile)
         {
-            // Unzip
-
             //the temp directory will be the package GUID - this keeps it consistent!
             //the zipName is always the package Guid.umb
 
@@ -765,48 +763,14 @@ namespace umbraco.cms.businesslogic.packager
             if (Directory.Exists(tempDir)) Directory.Delete(tempDir, true);
             Directory.CreateDirectory(tempDir);
 
-            var s = new ZipInputStream(File.OpenRead(zipName));
-
-            ZipEntry theEntry;
-            while ((theEntry = s.GetNextEntry()) != null)
-            {
-                string fileName = Path.GetFileName(theEntry.Name);
-
-                if (fileName != String.Empty)
-                {
-                    FileStream streamWriter = File.Create(tempDir + Path.DirectorySeparatorChar + fileName);
-
-                    int size = 2048;
-                    byte[] data = new byte[2048];
-                    while (true)
-                    {
-                        size = s.Read(data, 0, data.Length);
-                        if (size > 0)
-                        {
-                            streamWriter.Write(data, 0, size);
-                        }
-                        else
-                        {
-                            break;
-                        }
-                    }
-
-                    streamWriter.Close();
-
-                }
-            }
-
-            // Clean up
-            s.Close();
+            ZipFile.ExtractToDirectory(zipName, tempDir);
 
             if (deleteFile)
             {
                 File.Delete(zipName);
             }
 
-
             return tempDir;
-
         }
 
         #endregion
diff --git a/src/umbraco.cms/businesslogic/Packager/PackageInstance/utill.cs b/src/umbraco.cms/businesslogic/Packager/PackageInstance/utill.cs
index 2780bb4423..b1ca6696fe 100644
--- a/src/umbraco.cms/businesslogic/Packager/PackageInstance/utill.cs
+++ b/src/umbraco.cms/businesslogic/Packager/PackageInstance/utill.cs
@@ -11,13 +11,13 @@ using System.Web.UI.WebControls;
 using System.Web.UI.WebControls.WebParts;
 using System.Web.UI.HtmlControls;
 
-using System.IO;
+using System.IO;
+using System.IO.Compression;
 using System.Xml;
 
 using umbraco.cms.businesslogic.template;
 using umbraco.cms.businesslogic.web;
 using umbraco.cms.businesslogic.macro;
-using ICSharpCode.SharpZipLib.Zip;
 using Umbraco.Core;
 using Umbraco.Core.IO;
 
@@ -278,58 +278,24 @@ namespace umbraco.cms.businesslogic.packager
         /// <param name="savePath">The save path.</param>
         public static void ZipPackage(string Path, string savePath)
         {
-            string OutPath = savePath;
-
             ArrayList ar = GenerateFileList(Path);
             // generate file list
             // find number of chars to remove from orginal file path
-            int TrimLength = (Directory.GetParent(Path)).ToString().Length;
 
-            TrimLength += 1;
-
-            //remove '\'
-            FileStream ostream;
-
-            byte[] obuffer;
-
-            ZipOutputStream oZipStream = new ZipOutputStream(System.IO.File.Create(OutPath));
-            // create zip stream
-
-
-            oZipStream.SetLevel(9);
-            // 9 = maximum compression level
-            ZipEntry oZipEntry;
-
-            foreach (string Fil in ar) // for each file, generate a zipentry
+            using (var memoryStream = new MemoryStream())
             {
-                oZipEntry = new ZipEntry(Fil.Remove(0, TrimLength));
-                oZipStream.PutNextEntry(oZipEntry);
-
-
-                if (!Fil.EndsWith(@"/")) // if a file ends with '/' its a directory
+                using (var archive = new ZipArchive(memoryStream, ZipArchiveMode.Create))
                 {
-                    ostream = File.OpenRead(Fil);
-
-                    obuffer = new byte[ostream.Length];
-
-                    // byte buffer
-                    ostream.Read(obuffer, 0, obuffer.Length);
-
-                    oZipStream.Write(obuffer, 0, obuffer.Length);
-                    ostream.Close();
+                    foreach (string file in ar)
+                    {
+                        if (file.EndsWith(@"/") != true) // it's not a directory
+                        {
+                            archive.CreateEntryFromFile(file, System.IO.Path.GetFileName(file));
+                        }
+                    }
                 }
             }
-            oZipStream.Finish();
-            oZipStream.Close();
-            oZipStream.Dispose();
-            oZipStream = null;
-
-            oZipEntry = null;
-
-
-            ostream = null;
-            ar.Clear();
-            ar = null;
+            
         }
 
         private static ArrayList GenerateFileList(string Dir)
diff --git a/src/umbraco.cms/businesslogic/utilities/Zip.cs b/src/umbraco.cms/businesslogic/utilities/Zip.cs
index 36e9b6fc53..22450aa12f 100644
--- a/src/umbraco.cms/businesslogic/utilities/Zip.cs
+++ b/src/umbraco.cms/businesslogic/utilities/Zip.cs
@@ -1,9 +1,9 @@
 using System;
 using System.Collections.Generic;
-using System.IO;
+using System.IO;
+using System.IO.Compression;
 using System.Text;
 using System.Web;
-using ICSharpCode.SharpZipLib.Zip;
 using umbraco;
 
 namespace umbraco.cms.businesslogic.utilities
@@ -12,47 +12,13 @@ namespace umbraco.cms.businesslogic.utilities
     {
         public static void UnPack(string ZipFilePath, string UnPackDirectory, bool DeleteZipFile)
         {
-            // Unzip
-            string tempDir = UnPackDirectory;
-            Directory.CreateDirectory(tempDir);
-
-            ZipInputStream s = new ZipInputStream(File.OpenRead(ZipFilePath));
-
-            ZipEntry theEntry;
-            while ((theEntry = s.GetNextEntry()) != null)
+            if (Directory.Exists(UnPackDirectory) != true)
             {
-                string directoryName = Path.GetDirectoryName(theEntry.Name);
-                string fileName = Path.GetFileName(theEntry.Name);
-
-                if (fileName != String.Empty)
-                {
-                    FileStream streamWriter = File.Create(tempDir + Path.DirectorySeparatorChar + fileName);
-
-                    int size = 2048;
-                    byte[] data = new byte[2048];
-                    while (true)
-                    {
-                        size = s.Read(data, 0, data.Length);
-                        if (size > 0)
-                        {
-                            streamWriter.Write(data, 0, size);
-                        }
-                        else
-                        {
-                            break;
-                        }
-                    }
-
-                    streamWriter.Close();
-
-                }
-            }
-
-            // Clean up
-            s.Close();
+                Directory.CreateDirectory(UnPackDirectory);
+            }
+
             if (DeleteZipFile)
                 File.Delete(ZipFilePath);
-
         }
 
     }
diff --git a/src/umbraco.cms/umbraco.cms.csproj b/src/umbraco.cms/umbraco.cms.csproj
index 9defce9dde..792279ad10 100644
--- a/src/umbraco.cms/umbraco.cms.csproj
+++ b/src/umbraco.cms/umbraco.cms.csproj
@@ -129,6 +129,8 @@
       <Name>System.Data</Name>
     </Reference>
     <Reference Include="System.Drawing" />
+    <Reference Include="System.IO.Compression" />
+    <Reference Include="System.IO.Compression.FileSystem" />
     <Reference Include="System.Security">
       <Name>System.Security</Name>
     </Reference>