diff --git a/windows/LibEthereum.props b/windows/LibEthereum.props
index b85a36b55..8b9566af3 100644
--- a/windows/LibEthereum.props
+++ b/windows/LibEthereum.props
@@ -15,6 +15,7 @@
       <AdditionalIncludeDirectories>include/$(ProjectName);../libethereum;../../boost;../../leveldb/include;../../cryptopp;../secp256k1;../../miniupnp</AdditionalIncludeDirectories>
       <PreprocessorDefinitions>STATICLIB;LEVELDB_PLATFORM_WINDOWS;USE_NUM_BOOST;USE_FIELD_10X26;USE_FIELD_INV_BUILTIN;_WIN32_WINNT=0x0501;WIN32;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <RuntimeTypeInfo>true</RuntimeTypeInfo>
+      <MultiProcessorCompilation>true</MultiProcessorCompilation>
     </ClCompile>
     <Link>
       <AdditionalLibraryDirectories>../../boost/stage/$(Platform)</AdditionalLibraryDirectories>
diff --git a/windows/LibEthereum.vcxproj b/windows/LibEthereum.vcxproj
index e3432b328..a37eb4d6e 100644
--- a/windows/LibEthereum.vcxproj
+++ b/windows/LibEthereum.vcxproj
@@ -43,6 +43,13 @@
     <ClCompile Include="..\libethereum\TrieDB.cpp" />
     <ClCompile Include="..\libethereum\TrieHash.cpp" />
     <ClCompile Include="..\libethereum\UPnP.cpp" />
+    <ClCompile Include="stdafx.cpp">
+      <PrecompiledHeaderFile Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">stdafx.h</PrecompiledHeaderFile>
+      <PrecompiledHeader Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">Create</PrecompiledHeader>
+      <PrecompiledHeader Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">Create</PrecompiledHeader>
+      <PrecompiledHeader Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">Create</PrecompiledHeader>
+      <PrecompiledHeader Condition="'$(Configuration)|$(Platform)'=='Release|x64'">Create</PrecompiledHeader>
+    </ClCompile>
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="..\libethereum\AddressState.h" />
@@ -66,6 +73,7 @@
     <ClInclude Include="..\libethereum\TrieHash.h" />
     <ClInclude Include="..\libethereum\UPnP.h" />
     <ClInclude Include="..\libethereum\vector_ref.h" />
+    <ClInclude Include="stdafx.h" />
   </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="LibCryptoPP.vcxproj">
@@ -139,6 +147,8 @@
       <PreprocessorDefinitions>WIN32;_DEBUG;_LIB;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <MinimalRebuild>false</MinimalRebuild>
       <RuntimeLibrary>MultiThreadedDebug</RuntimeLibrary>
+      <PrecompiledHeader>Use</PrecompiledHeader>
+      <ForcedIncludeFiles>stdafx.h</ForcedIncludeFiles>
     </ClCompile>
     <Link>
       <SubSystem>Windows</SubSystem>
@@ -151,6 +161,8 @@
       <PreprocessorDefinitions>WIN32;_DEBUG;_LIB;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <MinimalRebuild>false</MinimalRebuild>
       <RuntimeLibrary>MultiThreadedDebug</RuntimeLibrary>
+      <ForcedIncludeFiles>stdafx.h</ForcedIncludeFiles>
+      <PrecompiledHeader>Use</PrecompiledHeader>
     </ClCompile>
     <Link>
       <SubSystem>Windows</SubSystem>
@@ -167,6 +179,8 @@
       <PreprocessorDefinitions>WIN32;NDEBUG;_LIB;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <TreatWarningAsError>true</TreatWarningAsError>
       <RuntimeLibrary>MultiThreaded</RuntimeLibrary>
+      <PrecompiledHeader>Use</PrecompiledHeader>
+      <ForcedIncludeFiles>stdafx.h</ForcedIncludeFiles>
     </ClCompile>
     <Link>
       <SubSystem>Windows</SubSystem>
@@ -183,6 +197,8 @@
       <PreprocessorDefinitions>WIN32;NDEBUG;_LIB;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <TreatWarningAsError>true</TreatWarningAsError>
       <RuntimeLibrary>MultiThreaded</RuntimeLibrary>
+      <PrecompiledHeader>Use</PrecompiledHeader>
+      <ForcedIncludeFiles>stdafx.h</ForcedIncludeFiles>
     </ClCompile>
     <Link>
       <SubSystem>Windows</SubSystem>
diff --git a/windows/LibEthereum.vcxproj.filters b/windows/LibEthereum.vcxproj.filters
index 29b24ad66..51ff81cdb 100644
--- a/windows/LibEthereum.vcxproj.filters
+++ b/windows/LibEthereum.vcxproj.filters
@@ -20,6 +20,9 @@
     <ClCompile Include="..\libethereum\AddressState.cpp" />
     <ClCompile Include="..\libethereum\BlockChain.cpp" />
     <ClCompile Include="..\libethereum\Instruction.cpp" />
+    <ClCompile Include="stdafx.cpp">
+      <Filter>Windows</Filter>
+    </ClCompile>
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="..\libethereum\BlockInfo.h" />
@@ -43,5 +46,13 @@
     <ClInclude Include="..\libethereum\vector_ref.h" />
     <ClInclude Include="..\libethereum\AddressState.h" />
     <ClInclude Include="..\libethereum\BlockChain.h" />
+    <ClInclude Include="stdafx.h">
+      <Filter>Windows</Filter>
+    </ClInclude>
+  </ItemGroup>
+  <ItemGroup>
+    <Filter Include="Windows">
+      <UniqueIdentifier>{2d571d8f-bacf-4c49-a0d0-c9036f5c0cc9}</UniqueIdentifier>
+    </Filter>
   </ItemGroup>
 </Project>
\ No newline at end of file
diff --git a/windows/TestEthereum.vcxproj b/windows/TestEthereum.vcxproj
index e275ce267..045be7b46 100644
--- a/windows/TestEthereum.vcxproj
+++ b/windows/TestEthereum.vcxproj
@@ -81,13 +81,13 @@
   </PropertyGroup>
   <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
     <ClCompile>
-      <PrecompiledHeader>
-      </PrecompiledHeader>
+      <PrecompiledHeader>Use</PrecompiledHeader>
       <Optimization>Disabled</Optimization>
       <PreprocessorDefinitions>WIN32;_DEBUG;_CONSOLE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <RuntimeLibrary>MultiThreadedDebug</RuntimeLibrary>
       <IntrinsicFunctions>true</IntrinsicFunctions>
       <OpenMPSupport>true</OpenMPSupport>
+      <ForcedIncludeFiles>stdafx.h</ForcedIncludeFiles>
     </ClCompile>
     <Link>
       <SubSystem>Console</SubSystem>
@@ -97,12 +97,12 @@
   </ItemDefinitionGroup>
   <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">
     <ClCompile>
-      <PrecompiledHeader>
-      </PrecompiledHeader>
+      <PrecompiledHeader>Use</PrecompiledHeader>
       <Optimization>Disabled</Optimization>
       <PreprocessorDefinitions>WIN32;_DEBUG;_CONSOLE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <RuntimeLibrary>MultiThreadedDebug</RuntimeLibrary>
       <IntrinsicFunctions>true</IntrinsicFunctions>
+      <ForcedIncludeFiles>stdafx.h</ForcedIncludeFiles>
     </ClCompile>
     <Link>
       <SubSystem>Console</SubSystem>
@@ -111,8 +111,7 @@
   </ItemDefinitionGroup>
   <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
     <ClCompile>
-      <PrecompiledHeader>
-      </PrecompiledHeader>
+      <PrecompiledHeader>Use</PrecompiledHeader>
       <Optimization>MaxSpeed</Optimization>
       <FunctionLevelLinking>true</FunctionLevelLinking>
       <IntrinsicFunctions>true</IntrinsicFunctions>
@@ -121,6 +120,7 @@
       <StringPooling>true</StringPooling>
       <InlineFunctionExpansion>AnySuitable</InlineFunctionExpansion>
       <OpenMPSupport>true</OpenMPSupport>
+      <ForcedIncludeFiles>stdafx.h</ForcedIncludeFiles>
     </ClCompile>
     <Link>
       <SubSystem>Console</SubSystem>
@@ -132,8 +132,7 @@
   </ItemDefinitionGroup>
   <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|x64'">
     <ClCompile>
-      <PrecompiledHeader>
-      </PrecompiledHeader>
+      <PrecompiledHeader>Use</PrecompiledHeader>
       <Optimization>MaxSpeed</Optimization>
       <FunctionLevelLinking>true</FunctionLevelLinking>
       <IntrinsicFunctions>true</IntrinsicFunctions>
@@ -142,6 +141,7 @@
       <StringPooling>true</StringPooling>
       <InlineFunctionExpansion>AnySuitable</InlineFunctionExpansion>
       <OpenMPSupport>true</OpenMPSupport>
+      <ForcedIncludeFiles>stdafx.h</ForcedIncludeFiles>
     </ClCompile>
     <Link>
       <SubSystem>Console</SubSystem>
@@ -165,6 +165,15 @@
     <ClCompile Include="..\test\state.cpp" />
     <ClCompile Include="..\test\trie.cpp" />
     <ClCompile Include="..\test\vm.cpp" />
+    <ClCompile Include="stdafx.cpp">
+      <PrecompiledHeader Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">Create</PrecompiledHeader>
+      <PrecompiledHeader Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">Create</PrecompiledHeader>
+      <PrecompiledHeader Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">Create</PrecompiledHeader>
+      <PrecompiledHeader Condition="'$(Configuration)|$(Platform)'=='Release|x64'">Create</PrecompiledHeader>
+    </ClCompile>
+  </ItemGroup>
+  <ItemGroup>
+    <ClInclude Include="stdafx.h" />
   </ItemGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
   <ImportGroup Label="ExtensionTargets">
diff --git a/windows/TestEthereum.vcxproj.filters b/windows/TestEthereum.vcxproj.filters
new file mode 100644
index 000000000..4f9afb9e9
--- /dev/null
+++ b/windows/TestEthereum.vcxproj.filters
@@ -0,0 +1,27 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <ItemGroup>
+    <ClCompile Include="..\test\crypto.cpp" />
+    <ClCompile Include="..\test\dagger.cpp" />
+    <ClCompile Include="..\test\hexPrefix.cpp" />
+    <ClCompile Include="..\test\main.cpp" />
+    <ClCompile Include="..\test\peer.cpp" />
+    <ClCompile Include="..\test\rlp.cpp" />
+    <ClCompile Include="..\test\state.cpp" />
+    <ClCompile Include="..\test\trie.cpp" />
+    <ClCompile Include="..\test\vm.cpp" />
+    <ClCompile Include="stdafx.cpp">
+      <Filter>Windows</Filter>
+    </ClCompile>
+  </ItemGroup>
+  <ItemGroup>
+    <Filter Include="Windows">
+      <UniqueIdentifier>{0acd7e2f-2594-4c13-94cb-3247045bdbfd}</UniqueIdentifier>
+    </Filter>
+  </ItemGroup>
+  <ItemGroup>
+    <ClInclude Include="stdafx.h">
+      <Filter>Windows</Filter>
+    </ClInclude>
+  </ItemGroup>
+</Project>
\ No newline at end of file
diff --git a/windows/stdafx.cpp b/windows/stdafx.cpp
new file mode 100644
index 000000000..d3c5fc299
--- /dev/null
+++ b/windows/stdafx.cpp
@@ -0,0 +1,21 @@
+/*
+	This file is part of cpp-ethereum.
+
+	cpp-ethereum is free software: you can redistribute it and/or modify
+	it under the terms of the GNU General Public License as published by
+	the Free Software Foundation, either version 3 of the License, or
+	(at your option) any later version.
+
+	cpp-ethereum is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+	GNU General Public License for more details.
+
+	You should have received a copy of the GNU General Public License
+	along with cpp-ethereum.  If not, see <http://www.gnu.org/licenses/>.
+*/
+/** @file stdafx.cpp
+ * @author Tim Hughes <tim@twistedfury.com>
+ * @date 2014
+ */
+
diff --git a/windows/stdafx.h b/windows/stdafx.h
new file mode 100644
index 000000000..1ad98d97b
--- /dev/null
+++ b/windows/stdafx.h
@@ -0,0 +1,42 @@
+/*
+	This file is part of cpp-ethereum.
+
+	cpp-ethereum is free software: you can redistribute it and/or modify
+	it under the terms of the GNU General Public License as published by
+	the Free Software Foundation, either version 3 of the License, or
+	(at your option) any later version.
+
+	cpp-ethereum is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+	GNU General Public License for more details.
+
+	You should have received a copy of the GNU General Public License
+	along with cpp-ethereum.  If not, see <http://www.gnu.org/licenses/>.
+*/
+/** @file stdafx.h
+ * @author Tim Hughes <tim@twistedfury.com>
+ * @date 2014
+ */
+
+#pragma once
+
+#include <ctime>
+#include <chrono>
+#include <array>
+#include <vector>
+#include <map>
+#include <unordered_map>
+#include <set>
+#include <array>
+#include <list>
+#include <set>
+#include <string>
+#include <cassert>
+#include <sstream>
+#include <cstdint>
+#include <type_traits>
+#include <assert.h>
+#include <boost/filesystem.hpp>
+#include <boost/multiprecision/cpp_int.hpp>
+#include <boost/thread.hpp>