diff --git a/OpenHtmlToPdf.Tests/HtmlToPdfConversion.cs b/OpenHtmlToPdf.Tests/HtmlToPdfConversion.cs
index 811dd59b..dccdeb50 100644
--- a/OpenHtmlToPdf.Tests/HtmlToPdfConversion.cs
+++ b/OpenHtmlToPdf.Tests/HtmlToPdfConversion.cs
@@ -159,7 +159,7 @@ public void Convert_multiple_documents_concurrently()
             var tasks = new List<Task<byte[]>>();
 
             for (var i = 0; i < documentCount; i++)
-                tasks.Add(Task.Run(() => Pdf.From(html).Content()));
+                tasks.Add(Task.Factory.StartNew(() => Pdf.From(html).Content()));
 
             Task.WaitAll(tasks.OfType<Task>().ToArray());
 
@@ -202,7 +202,7 @@ public void Convert_massive_number_of_documents()
             var tasks = new List<Task<byte[]>>();
 
             for (var i = 0; i < documentCount; i++)
-                tasks.Add(Task.Run(() => Pdf.From(html).Content()));
+                tasks.Add(Task.Factory.StartNew(() => Pdf.From(html).Content()));
 
             Task.WaitAll(tasks.OfType<Task>().ToArray());
 
diff --git a/OpenHtmlToPdf.Tests/OpenHtmlToPdf.Tests.csproj b/OpenHtmlToPdf.Tests/OpenHtmlToPdf.Tests.csproj
index fe005779..72a2dd13 100644
--- a/OpenHtmlToPdf.Tests/OpenHtmlToPdf.Tests.csproj
+++ b/OpenHtmlToPdf.Tests/OpenHtmlToPdf.Tests.csproj
@@ -8,7 +8,7 @@
     <AppDesignerFolder>Properties</AppDesignerFolder>
     <RootNamespace>OpenHtmlToPdf.Tests</RootNamespace>
     <AssemblyName>OpenHtmlToPdf.Tests</AssemblyName>
-    <TargetFrameworkVersion>v4.5</TargetFrameworkVersion>
+    <TargetFrameworkVersion>v4.0</TargetFrameworkVersion>
     <FileAlignment>512</FileAlignment>
     <ProjectTypeGuids>{3AC096D0-A1C2-E12C-1390-A8335801FDAB};{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}</ProjectTypeGuids>
     <VisualStudioVersion Condition="'$(VisualStudioVersion)' == ''">10.0</VisualStudioVersion>
@@ -18,6 +18,7 @@
     <TestProjectType>UnitTest</TestProjectType>
     <SolutionDir Condition="$(SolutionDir) == '' Or $(SolutionDir) == '*Undefined*'">..\</SolutionDir>
     <RestorePackages>true</RestorePackages>
+    <TargetFrameworkProfile />
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
     <DebugSymbols>true</DebugSymbols>
diff --git a/OpenHtmlToPdf.WkHtmlToPdf/App.config b/OpenHtmlToPdf.WkHtmlToPdf/App.config
index 8e156463..74ade9db 100644
--- a/OpenHtmlToPdf.WkHtmlToPdf/App.config
+++ b/OpenHtmlToPdf.WkHtmlToPdf/App.config
@@ -1,6 +1,6 @@
-<?xml version="1.0" encoding="utf-8" ?>
+<?xml version="1.0" encoding="utf-8"?>
 <configuration>
     <startup> 
-        <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5" />
+        <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.0"/>
     </startup>
-</configuration>
\ No newline at end of file
+</configuration>
diff --git a/OpenHtmlToPdf.WkHtmlToPdf/Assets/ZipArchiveHelper.cs b/OpenHtmlToPdf.WkHtmlToPdf/Assets/ZipArchiveHelper.cs
index 86abc08d..ffb55381 100644
--- a/OpenHtmlToPdf.WkHtmlToPdf/Assets/ZipArchiveHelper.cs
+++ b/OpenHtmlToPdf.WkHtmlToPdf/Assets/ZipArchiveHelper.cs
@@ -1,4 +1,5 @@
-using System.IO;
+using Ionic.Zip;
+using System.IO;
 using System.IO.Compression;
 using System.Linq;
 
@@ -6,18 +7,18 @@ namespace OpenHtmlToPdf.WkHtmlToPdf.Assets
 {
     static class ZipArchiveHelper
     {
-        public static byte[] ReadFile(this ZipArchive zipArchive, string filename)
+        public static byte[] ReadFile(this ZipFile zipFile, string filename)
         {
-            return zipArchive.Entries
-                .Where(e => e.FullName == filename)
+            return zipFile.Entries
+                .Where(e => e.FileName == filename)
                 .Select(Read).Single();
         }
 
-        private static byte[] Read(this ZipArchiveEntry zipArchiveEntry)
+        private static byte[] Read(this ZipEntry zipEntry)
         {
-            using (var stream = zipArchiveEntry.Open())
+            using (var stream = zipEntry.OpenReader())
             {
-                return stream.Read(zipArchiveEntry.Length);
+                return stream.Read(zipEntry.UncompressedSize);
             }
         }
 
diff --git a/OpenHtmlToPdf.WkHtmlToPdf/OpenHtmlToPdf.WkHtmlToPdf.csproj b/OpenHtmlToPdf.WkHtmlToPdf/OpenHtmlToPdf.WkHtmlToPdf.csproj
index fe3c6bed..ee4738b8 100644
--- a/OpenHtmlToPdf.WkHtmlToPdf/OpenHtmlToPdf.WkHtmlToPdf.csproj
+++ b/OpenHtmlToPdf.WkHtmlToPdf/OpenHtmlToPdf.WkHtmlToPdf.csproj
@@ -9,10 +9,13 @@
     <AppDesignerFolder>Properties</AppDesignerFolder>
     <RootNamespace>OpenHtmlToPdf.WkHtmlToPdf</RootNamespace>
     <AssemblyName>OpenHtmlToPdf.WkHtmlToPdf</AssemblyName>
-    <TargetFrameworkVersion>v4.5</TargetFrameworkVersion>
+    <TargetFrameworkVersion>v4.0</TargetFrameworkVersion>
     <FileAlignment>512</FileAlignment>
     <SolutionDir Condition="$(SolutionDir) == '' Or $(SolutionDir) == '*Undefined*'">..\</SolutionDir>
     <RestorePackages>true</RestorePackages>
+    <TargetFrameworkProfile />
+    <NuGetPackageImportStamp>
+    </NuGetPackageImportStamp>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
     <PlatformTarget>AnyCPU</PlatformTarget>
@@ -40,9 +43,11 @@
     </StartupObject>
   </PropertyGroup>
   <ItemGroup>
+    <Reference Include="DotNetZip, Version=1.13.8.0, Culture=neutral, PublicKeyToken=6583c7c814667745, processorArchitecture=MSIL">
+      <HintPath>..\packages\DotNetZip.1.13.8\lib\net40\DotNetZip.dll</HintPath>
+    </Reference>
     <Reference Include="System" />
     <Reference Include="System.Core" />
-    <Reference Include="System.IO.Compression" />
     <Reference Include="System.Runtime.Serialization" />
     <Reference Include="System.Xml.Linq" />
     <Reference Include="System.Data.DataSetExtensions" />
@@ -73,6 +78,7 @@
   <ItemGroup>
     <None Include="App.config" />
     <EmbeddedResource Include="Assets\wkhtmltox.zip" />
+    <None Include="packages.config" />
   </ItemGroup>
   <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
   <Import Project="$(SolutionDir)\.nuget\NuGet.targets" Condition="Exists('$(SolutionDir)\.nuget\NuGet.targets')" />
diff --git a/OpenHtmlToPdf.WkHtmlToPdf/WkHtmlToX/WkHtmlToPdfLibrary.cs b/OpenHtmlToPdf.WkHtmlToPdf/WkHtmlToX/WkHtmlToPdfLibrary.cs
index e705caa5..3b39fe80 100644
--- a/OpenHtmlToPdf.WkHtmlToPdf/WkHtmlToX/WkHtmlToPdfLibrary.cs
+++ b/OpenHtmlToPdf.WkHtmlToPdf/WkHtmlToX/WkHtmlToPdfLibrary.cs
@@ -2,6 +2,7 @@
 using System.IO;
 using System.IO.Compression;
 using System.Reflection;
+using Ionic.Zip;
 using OpenHtmlToPdf.WkHtmlToPdf.Assets;
 using OpenHtmlToPdf.WkHtmlToPdf.Interop;
 
@@ -23,15 +24,15 @@ private static byte[] LoadLibraryContent()
             if (Environment.OSVersion.Platform != PlatformID.Win32NT)
                 throw new PlatformNotSupportedException(String.Format("Platform {0} is not supported", Platform()));
 
-            using (var wkhtmltoxZipArchive = WkHtmlToXZipArchive())
+            using (var wkhtmltoxZipArchive = WkHtmlToXZipFile())
             {
                 return wkhtmltoxZipArchive.ReadFile(CompressedLibraryFilename());
             }
         }
 
-        private static ZipArchive WkHtmlToXZipArchive()
+        private static ZipFile WkHtmlToXZipFile()
         {
-            return new ZipArchive(GetManifestResourceStream());
+            return ZipFile.Read(GetManifestResourceStream());
         }
 
         private static Stream GetManifestResourceStream()
diff --git a/OpenHtmlToPdf.WkHtmlToPdf/packages.config b/OpenHtmlToPdf.WkHtmlToPdf/packages.config
new file mode 100644
index 00000000..ceee4656
--- /dev/null
+++ b/OpenHtmlToPdf.WkHtmlToPdf/packages.config
@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="utf-8"?>
+<packages>
+  <package id="DotNetZip" version="1.13.8" targetFramework="net40" />
+</packages>
\ No newline at end of file
diff --git a/OpenHtmlToPdf/Assets/ConverterExecutable.cs b/OpenHtmlToPdf/Assets/ConverterExecutable.cs
index 17a30e9d..f440ef9f 100644
--- a/OpenHtmlToPdf/Assets/ConverterExecutable.cs
+++ b/OpenHtmlToPdf/Assets/ConverterExecutable.cs
@@ -7,6 +7,7 @@ namespace OpenHtmlToPdf.Assets
     sealed class ConverterExecutable
     {
         private const string ConverterExecutableFilename = "OpenHtmlToPdf.WkHtmlToPdf.exe";
+        private const string ConverterExecutableReferenceFilename = "DotNetZip.dll";
 
         private ConverterExecutable()
         {
@@ -21,6 +22,13 @@ public static ConverterExecutable Get()
             return bundledFile;
         }
 
+
+        public string FullConverterExecutableReferenceFilename
+        {
+            get { return ResolveFullPathToConverterExecutableReferenceFile(); }
+        }
+
+
         public string FullConverterExecutableFilename
         {
             get { return ResolveFullPathToConverterExecutableFile(); }
@@ -28,13 +36,17 @@ public string FullConverterExecutableFilename
 
         private void CreateIfConverterExecutableDoesNotExist()
         {
+            if (!File.Exists(FullConverterExecutableReferenceFilename))
+                Create(GetConverterExecutableContent(GetConverterReferenceExecutable()), FullConverterExecutableReferenceFilename);
+
             if (!File.Exists(FullConverterExecutableFilename))
-                Create(GetConverterExecutableContent());
+                Create(GetConverterExecutableContent(GetConverterExecutable()), FullConverterExecutableFilename);
+
         }
 
-        private static byte[] GetConverterExecutableContent()
+        private static byte[] GetConverterExecutableContent(Stream stream)
         {
-            using (var resourceStream = GetConverterExecutable())
+            using (var resourceStream = stream)
             {
                 var resource = new byte[resourceStream.Length];
 
@@ -44,12 +56,21 @@ private static byte[] GetConverterExecutableContent()
             }
         }
 
+
+
         private static Stream GetConverterExecutable()
         {
             return Assembly.GetExecutingAssembly().GetManifestResourceStream("OpenHtmlToPdf.Assets.OpenHtmlToPdf.WkHtmlToPdf.exe");
         }
 
-        private void Create(byte[] fileContent)
+        private static Stream GetConverterReferenceExecutable()
+        {
+            return Assembly.GetExecutingAssembly().GetManifestResourceStream("OpenHtmlToPdf.Assets.DotNetZip.dll");
+        }
+
+
+
+        private void Create(byte[] fileContent, string Name)
         {
             try
             {
@@ -57,7 +78,7 @@ private void Create(byte[] fileContent)
                     Directory.CreateDirectory(BundledFilesDirectory());
 
 
-                using (var file = File.Open(FullConverterExecutableFilename, FileMode.Create))
+                using (var file = File.Open(Name, FileMode.Create))
                 {
 
                     file.Write(fileContent, 0, fileContent.Length);
@@ -73,6 +94,11 @@ private static string ResolveFullPathToConverterExecutableFile()
             return Path.Combine(BundledFilesDirectory(), ConverterExecutableFilename);
         }
 
+        private static string ResolveFullPathToConverterExecutableReferenceFile()
+        {
+            return Path.Combine(BundledFilesDirectory(), ConverterExecutableReferenceFilename);
+        }
+
         private static string BundledFilesDirectory()
         {
             return Path.Combine(Path.GetTempPath(), "OpenHtmlToPdf", Version());
diff --git a/OpenHtmlToPdf/Assets/DotNetZip.dll b/OpenHtmlToPdf/Assets/DotNetZip.dll
new file mode 100644
index 00000000..9d1e57ec
Binary files /dev/null and b/OpenHtmlToPdf/Assets/DotNetZip.dll differ
diff --git a/OpenHtmlToPdf/Assets/OpenHtmlToPdf.WkHtmlToPdf.exe b/OpenHtmlToPdf/Assets/OpenHtmlToPdf.WkHtmlToPdf.exe
index f8421b37..c414a010 100644
Binary files a/OpenHtmlToPdf/Assets/OpenHtmlToPdf.WkHtmlToPdf.exe and b/OpenHtmlToPdf/Assets/OpenHtmlToPdf.WkHtmlToPdf.exe differ
diff --git a/OpenHtmlToPdf/Key.snk b/OpenHtmlToPdf/Key.snk
new file mode 100644
index 00000000..770071cb
Binary files /dev/null and b/OpenHtmlToPdf/Key.snk differ
diff --git a/OpenHtmlToPdf/OpenHtmlToPdf.csproj b/OpenHtmlToPdf/OpenHtmlToPdf.csproj
index 35b4232e..e32040e0 100644
--- a/OpenHtmlToPdf/OpenHtmlToPdf.csproj
+++ b/OpenHtmlToPdf/OpenHtmlToPdf.csproj
@@ -10,7 +10,7 @@
     <AppDesignerFolder>Properties</AppDesignerFolder>
     <RootNamespace>OpenHtmlToPdf</RootNamespace>
     <AssemblyName>OpenHtmlToPdf</AssemblyName>
-    <TargetFrameworkVersion>v4.5</TargetFrameworkVersion>
+    <TargetFrameworkVersion>v4.0</TargetFrameworkVersion>
     <FileAlignment>512</FileAlignment>
     <SolutionDir Condition="$(SolutionDir) == '' Or $(SolutionDir) == '*Undefined*'">..\</SolutionDir>
     <RestorePackages>true</RestorePackages>
@@ -95,10 +95,15 @@
   <PropertyGroup>
     <StartupObject />
   </PropertyGroup>
+  <PropertyGroup>
+    <SignAssembly>true</SignAssembly>
+  </PropertyGroup>
+  <PropertyGroup>
+    <AssemblyOriginatorKeyFile>Key.snk</AssemblyOriginatorKeyFile>
+  </PropertyGroup>
   <ItemGroup>
     <Reference Include="System" />
     <Reference Include="System.Drawing" />
-    <Reference Include="System.IO.Compression" />
     <Reference Include="System.Runtime.Serialization" />
     <Reference Include="System.XML" />
   </ItemGroup>
@@ -119,9 +124,12 @@
     <Compile Include="Properties\AssemblyInfo.cs" />
     <Compile Include="HtmlToPdfConverterProcess.cs" />
     <Compile Include="TemporaryPdf.cs" />
+    <None Include="Key.snk" />
     <None Include="Properties\OpenHtmlToPdf.nuspec" />
   </ItemGroup>
-  <ItemGroup />
+  <ItemGroup>
+    <EmbeddedResource Include="Assets\DotNetZip.dll" />
+  </ItemGroup>
   <ItemGroup>
     <EmbeddedResource Include="Assets\OpenHtmlToPdf.WkHtmlToPdf.exe" />
   </ItemGroup>
diff --git a/OpenHtmlToPdf/Properties/AssemblyInfo.cs b/OpenHtmlToPdf/Properties/AssemblyInfo.cs
index 7f45ceb2..8f1565a7 100644
--- a/OpenHtmlToPdf/Properties/AssemblyInfo.cs
+++ b/OpenHtmlToPdf/Properties/AssemblyInfo.cs
@@ -31,5 +31,5 @@
 // You can specify all the values or you can default the Build and Revision Numbers 
 // by using the '*' as shown below:
 // [assembly: AssemblyVersion("1.0.*")]
-[assembly: AssemblyVersion("1.12.0")]
-[assembly: AssemblyFileVersion("1.12.0")]
+[assembly: AssemblyVersion("1.12.1")]
+[assembly: AssemblyFileVersion("1.12.1")]