diff --git a/src/CalcManager/CEngine/CalcInput.cpp b/src/CalcManager/CEngine/CalcInput.cpp
index 45e553b9..1c47a8da 100644
--- a/src/CalcManager/CEngine/CalcInput.cpp
+++ b/src/CalcManager/CEngine/CalcInput.cpp
@@ -1,7 +1,7 @@
 // Copyright (c) Microsoft Corporation. All rights reserved.
 // Licensed under the MIT License.
 
-#include "pch.h"
+#include <sstream>
 #include "Header Files/CalcEngine.h"
 
 using namespace std;
diff --git a/src/CalcManager/CEngine/CalcUtils.cpp b/src/CalcManager/CEngine/CalcUtils.cpp
index 7980e4e0..15b11926 100644
--- a/src/CalcManager/CEngine/CalcUtils.cpp
+++ b/src/CalcManager/CEngine/CalcUtils.cpp
@@ -1,7 +1,6 @@
 // Copyright (c) Microsoft Corporation. All rights reserved.
 // Licensed under the MIT License.
 
-#include "pch.h"
 #include "Header Files/CalcEngine.h"
 #include "Header Files/CalcUtils.h"
 
diff --git a/src/CalcManager/CEngine/History.cpp b/src/CalcManager/CEngine/History.cpp
index ca276a41..74edf3cc 100644
--- a/src/CalcManager/CEngine/History.cpp
+++ b/src/CalcManager/CEngine/History.cpp
@@ -1,7 +1,6 @@
 // Copyright (c) Microsoft Corporation. All rights reserved.
 // Licensed under the MIT License.
 
-#include "pch.h"
 #include "Header Files/CalcEngine.h"
 #include "Command.h"
 #include "CalculatorVector.h"
diff --git a/src/CalcManager/CEngine/Number.cpp b/src/CalcManager/CEngine/Number.cpp
index 4bf83a33..fdf29e09 100644
--- a/src/CalcManager/CEngine/Number.cpp
+++ b/src/CalcManager/CEngine/Number.cpp
@@ -1,6 +1,6 @@
 // Copyright (c) Microsoft Corporation. All rights reserved.
 
-#include "pch.h"
+#include <algorithm>
 #include "Header Files/Number.h"
 
 using namespace std;
diff --git a/src/CalcManager/CEngine/Rational.cpp b/src/CalcManager/CEngine/Rational.cpp
index c93c79a6..e116c237 100644
--- a/src/CalcManager/CEngine/Rational.cpp
+++ b/src/CalcManager/CEngine/Rational.cpp
@@ -1,6 +1,6 @@
 // Copyright (c) Microsoft Corporation. All rights reserved.
 
-#include "pch.h"
+#include <intsafe.h>
 #include "Header Files/Rational.h"
 
 using namespace std;
diff --git a/src/CalcManager/CEngine/RationalMath.cpp b/src/CalcManager/CEngine/RationalMath.cpp
index f5de74fc..4b1a4b8a 100644
--- a/src/CalcManager/CEngine/RationalMath.cpp
+++ b/src/CalcManager/CEngine/RationalMath.cpp
@@ -1,7 +1,6 @@
 // Copyright (c) Microsoft Corporation. All rights reserved.
 // Licensed under the MIT License.
 
-#include "pch.h"
 #include "Header Files/RationalMath.h"
 
 using namespace std;
diff --git a/src/CalcManager/CEngine/calc.cpp b/src/CalcManager/CEngine/calc.cpp
index 0e4979f2..65e6f0d0 100644
--- a/src/CalcManager/CEngine/calc.cpp
+++ b/src/CalcManager/CEngine/calc.cpp
@@ -1,9 +1,8 @@
 // Copyright (c) Microsoft Corporation. All rights reserved.
 // Licensed under the MIT License.
 
-#include "pch.h"
+#include <cassert>
 #include "Header Files/CalcEngine.h"
-
 #include "CalculatorResource.h"
 
 using namespace std;
diff --git a/src/CalcManager/CEngine/scicomm.cpp b/src/CalcManager/CEngine/scicomm.cpp
index 4e0322d0..36130bb5 100644
--- a/src/CalcManager/CEngine/scicomm.cpp
+++ b/src/CalcManager/CEngine/scicomm.cpp
@@ -12,7 +12,8 @@
 *
 * Author:
 \****************************************************************************/
-#include "pch.h"
+
+#include <string>
 #include "Header Files/CalcEngine.h"
 #include "Header Files/CalcUtils.h"
 
diff --git a/src/CalcManager/CEngine/scidisp.cpp b/src/CalcManager/CEngine/scidisp.cpp
index 849fe863..1ef88799 100644
--- a/src/CalcManager/CEngine/scidisp.cpp
+++ b/src/CalcManager/CEngine/scidisp.cpp
@@ -12,7 +12,9 @@
 *
 * Author:
 \****************************************************************************/
-#include "pch.h"
+
+#include <sstream>
+#include <regex>
 #include "Header Files/CalcEngine.h"
 
 using namespace std;
diff --git a/src/CalcManager/CEngine/scifunc.cpp b/src/CalcManager/CEngine/scifunc.cpp
index a1007c1c..c2341752 100644
--- a/src/CalcManager/CEngine/scifunc.cpp
+++ b/src/CalcManager/CEngine/scifunc.cpp
@@ -16,7 +16,6 @@
 /***                                                                    ***/
 /***                                                                    ***/
 /**************************************************************************/
-#include "pch.h"
 #include "Header Files/CalcEngine.h"
 
 using namespace std;
diff --git a/src/CalcManager/CEngine/scioper.cpp b/src/CalcManager/CEngine/scioper.cpp
index 9ced7021..f8d04855 100644
--- a/src/CalcManager/CEngine/scioper.cpp
+++ b/src/CalcManager/CEngine/scioper.cpp
@@ -1,7 +1,6 @@
 // Copyright (c) Microsoft Corporation. All rights reserved.
 // Licensed under the MIT License.
 
-#include "pch.h"
 #include "Header Files/CalcEngine.h"
 
 using namespace CalcEngine;
diff --git a/src/CalcManager/CEngine/sciset.cpp b/src/CalcManager/CEngine/sciset.cpp
index 5495748e..ca715be5 100644
--- a/src/CalcManager/CEngine/sciset.cpp
+++ b/src/CalcManager/CEngine/sciset.cpp
@@ -1,7 +1,6 @@
 // Copyright (c) Microsoft Corporation. All rights reserved.
 // Licensed under the MIT License.
 
-#include "pch.h"
 #include "Header Files/CalcEngine.h"
 
 using namespace CalcEngine;
diff --git a/src/CalcManager/CalcManager.vcxproj b/src/CalcManager/CalcManager.vcxproj
index 4a098141..4d03a5c9 100644
--- a/src/CalcManager/CalcManager.vcxproj
+++ b/src/CalcManager/CalcManager.vcxproj
@@ -157,6 +157,7 @@
       <AdditionalIncludeDirectories>$(SolutionDir)..\src\;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
       <WarningLevel>Level4</WarningLevel>
       <TreatWarningAsError>true</TreatWarningAsError>
+      <ForcedIncludeFiles>pch.h</ForcedIncludeFiles>
     </ClCompile>
     <Link>
       <SubSystem>Console</SubSystem>
@@ -173,6 +174,7 @@
       <AdditionalIncludeDirectories>$(SolutionDir)..\src\;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
       <WarningLevel>Level4</WarningLevel>
       <TreatWarningAsError>true</TreatWarningAsError>
+      <ForcedIncludeFiles>pch.h</ForcedIncludeFiles>
     </ClCompile>
     <Link>
       <SubSystem>Console</SubSystem>
@@ -189,6 +191,7 @@
       <AdditionalIncludeDirectories>$(SolutionDir)..\src\;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
       <WarningLevel>Level4</WarningLevel>
       <TreatWarningAsError>true</TreatWarningAsError>
+      <ForcedIncludeFiles>pch.h</ForcedIncludeFiles>
     </ClCompile>
     <Link>
       <SubSystem>Console</SubSystem>
@@ -205,6 +208,7 @@
       <AdditionalIncludeDirectories>$(SolutionDir)..\src\;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
       <WarningLevel>Level4</WarningLevel>
       <TreatWarningAsError>true</TreatWarningAsError>
+      <ForcedIncludeFiles>pch.h</ForcedIncludeFiles>
     </ClCompile>
     <Link>
       <SubSystem>Console</SubSystem>
@@ -222,6 +226,7 @@
       <AdditionalIncludeDirectories>$(SolutionDir)..\src\;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
       <WarningLevel>Level4</WarningLevel>
       <TreatWarningAsError>true</TreatWarningAsError>
+      <ForcedIncludeFiles>pch.h</ForcedIncludeFiles>
     </ClCompile>
     <Link>
       <SubSystem>Console</SubSystem>
@@ -238,6 +243,7 @@
       <AdditionalIncludeDirectories>$(SolutionDir)..\src\;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
       <WarningLevel>Level4</WarningLevel>
       <TreatWarningAsError>true</TreatWarningAsError>
+      <ForcedIncludeFiles>pch.h</ForcedIncludeFiles>
     </ClCompile>
     <Link>
       <SubSystem>Console</SubSystem>
@@ -254,6 +260,7 @@
       <AdditionalIncludeDirectories>$(SolutionDir)..\src\;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
       <WarningLevel>Level4</WarningLevel>
       <TreatWarningAsError>true</TreatWarningAsError>
+      <ForcedIncludeFiles>pch.h</ForcedIncludeFiles>
     </ClCompile>
     <Link>
       <SubSystem>Console</SubSystem>
@@ -270,6 +277,7 @@
       <AdditionalIncludeDirectories>$(SolutionDir)..\src\;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
       <WarningLevel>Level4</WarningLevel>
       <TreatWarningAsError>true</TreatWarningAsError>
+      <ForcedIncludeFiles>pch.h</ForcedIncludeFiles>
     </ClCompile>
     <Link>
       <SubSystem>Console</SubSystem>
@@ -278,7 +286,6 @@
     </Link>
   </ItemDefinitionGroup>
   <ItemGroup>
-    <ClInclude Include="CalcException.h" />
     <ClInclude Include="CalculatorHistory.h" />
     <ClInclude Include="CalculatorManager.h" />
     <ClInclude Include="CalculatorResource.h" />
diff --git a/src/CalcManager/CalculatorHistory.cpp b/src/CalcManager/CalculatorHistory.cpp
index 31a1dae2..935ea8da 100644
--- a/src/CalcManager/CalculatorHistory.cpp
+++ b/src/CalcManager/CalculatorHistory.cpp
@@ -1,7 +1,7 @@
-// Copyright (c) Microsoft Corporation. All rights reserved.
+// Copyright (c) Microsoft Corporation. All rights reserved.
 // Licensed under the MIT License.
 
-#include "pch.h"
+#include <cassert>
 #include "CalculatorHistory.h"
 
 using namespace std;
diff --git a/src/CalcManager/CalculatorManager.cpp b/src/CalcManager/CalculatorManager.cpp
index d5bbd029..e640bd94 100644
--- a/src/CalcManager/CalculatorManager.cpp
+++ b/src/CalcManager/CalculatorManager.cpp
@@ -1,7 +1,7 @@
 // Copyright (c) Microsoft Corporation. All rights reserved.
 // Licensed under the MIT License.
 
-#include "pch.h"
+#include <climits> // for UCHAR_MAX
 #include "Header Files/CalcEngine.h"
 #include "CalculatorManager.h"
 #include "CalculatorResource.h"
diff --git a/src/CalcManager/CalculatorVector.h b/src/CalcManager/CalculatorVector.h
index a4de434d..e9f1b8dc 100644
--- a/src/CalcManager/CalculatorVector.h
+++ b/src/CalcManager/CalculatorVector.h
@@ -1,9 +1,14 @@
-// Copyright (c) Microsoft Corporation. All rights reserved.
+// Copyright (c) Microsoft Corporation. All rights reserved.
 // Licensed under the MIT License.
 
 #pragma once
 
+#include <string>
+#include <vector>
+#include <winerror.h>
 #include "Ratpack/CalcErr.h"
+#include <stdexcept> // for std::out_of_range
+#include <sal.h> // for SAL
 
 template <typename TType>
 class CalculatorVector
diff --git a/src/CalcManager/Command.h b/src/CalcManager/Command.h
index e6eeb8ac..4d98d012 100644
--- a/src/CalcManager/Command.h
+++ b/src/CalcManager/Command.h
@@ -1,4 +1,4 @@
-// Copyright (c) Microsoft Corporation. All rights reserved.
+// Copyright (c) Microsoft Corporation. All rights reserved.
 // Licensed under the MIT License.
 
 #pragma once
diff --git a/src/CalcManager/ExpressionCommand.cpp b/src/CalcManager/ExpressionCommand.cpp
index 0b68a374..9fc87708 100644
--- a/src/CalcManager/ExpressionCommand.cpp
+++ b/src/CalcManager/ExpressionCommand.cpp
@@ -1,7 +1,7 @@
 // Copyright (c) Microsoft Corporation. All rights reserved.
 // Licensed under the MIT License.
 
-#include "pch.h"
+#include <string>
 #include "Header Files/CCommand.h"
 #include "CalculatorVector.h"
 #include "ExpressionCommand.h"
diff --git a/src/CalcManager/ExpressionCommandInterface.h b/src/CalcManager/ExpressionCommandInterface.h
index ce89dd81..94bae836 100644
--- a/src/CalcManager/ExpressionCommandInterface.h
+++ b/src/CalcManager/ExpressionCommandInterface.h
@@ -1,7 +1,9 @@
-// Copyright (c) Microsoft Corporation. All rights reserved.
+// Copyright (c) Microsoft Corporation. All rights reserved.
 // Licensed under the MIT License.
 
 #pragma once
+
+#include <memory> // for std::shared_ptr
 #include "CalculatorVector.h"
 #include "Command.h"
 
diff --git a/src/CalcManager/Header Files/CCommand.h b/src/CalcManager/Header Files/CCommand.h
index 2fc08b3c..9530b5c5 100644
--- a/src/CalcManager/Header Files/CCommand.h	
+++ b/src/CalcManager/Header Files/CCommand.h	
@@ -13,6 +13,8 @@
 *
 \****************************************************************************/
 
+#pragma once
+
 // The following are the valid id's which can be passed to CCalcEngine::ProcessCommand
 
 #define IDM_HEX           313
diff --git a/src/CalcManager/Header Files/EngineStrings.h b/src/CalcManager/Header Files/EngineStrings.h
index 37f11483..89d624bf 100644
--- a/src/CalcManager/Header Files/EngineStrings.h	
+++ b/src/CalcManager/Header Files/EngineStrings.h	
@@ -13,6 +13,11 @@
 * Created: 13-Feb-2008
 *
 \****************************************************************************/
+
+#pragma once
+
+#include <string>
+
 inline constexpr auto IDS_ERRORS_FIRST = 99;
 
 // This is the list of error strings corresponding to SCERR_DIVIDEZERO..
diff --git a/src/CalcManager/Header Files/History.h b/src/CalcManager/Header Files/History.h
index 4f82088f..7446616d 100644
--- a/src/CalcManager/Header Files/History.h	
+++ b/src/CalcManager/Header Files/History.h	
@@ -3,6 +3,7 @@
 
 #pragma once
 
+#include <array>
 #include "ICalcDisplay.h"
 #include "IHistoryDisplay.h"
 #include "Rational.h"
diff --git a/src/CalcManager/Header Files/Number.h b/src/CalcManager/Header Files/Number.h
index c67aa108..769e3acf 100644
--- a/src/CalcManager/Header Files/Number.h	
+++ b/src/CalcManager/Header Files/Number.h	
@@ -3,6 +3,7 @@
 
 #pragma once
 
+#include <vector>
 #include "Ratpack/ratpak.h"
 
 namespace CalcEngine
diff --git a/src/CalcManager/Ratpack/basex.cpp b/src/CalcManager/Ratpack/basex.cpp
index 97a29dd4..2685af87 100644
--- a/src/CalcManager/Ratpack/basex.cpp
+++ b/src/CalcManager/Ratpack/basex.cpp
@@ -14,8 +14,8 @@
 //  internal base is a power of 2.
 //
 //-----------------------------------------------------------------------------
-#include "pch.h"
 #include "ratpak.h"
+#include <cstring> // for memmove
 
 void _mulnumx( PNUMBER *pa, PNUMBER b );
 
diff --git a/src/CalcManager/Ratpack/conv.cpp b/src/CalcManager/Ratpack/conv.cpp
index c25d4481..3a1aaa14 100644
--- a/src/CalcManager/Ratpack/conv.cpp
+++ b/src/CalcManager/Ratpack/conv.cpp
@@ -17,7 +17,10 @@
 //
 //---------------------------------------------------------------------------
 
-#include "pch.h"
+#include <algorithm>
+#include <winerror.h>
+#include <sstream>
+#include <cstring> // for memmove, memcpy
 #include "ratpak.h"
 
 using namespace std;
diff --git a/src/CalcManager/Ratpack/exp.cpp b/src/CalcManager/Ratpack/exp.cpp
index 95637404..e4939db4 100644
--- a/src/CalcManager/Ratpack/exp.cpp
+++ b/src/CalcManager/Ratpack/exp.cpp
@@ -14,7 +14,6 @@
 //
 //
 //-----------------------------------------------------------------------------
-#include "pch.h"
 #include "ratpak.h"
 
 
diff --git a/src/CalcManager/Ratpack/fact.cpp b/src/CalcManager/Ratpack/fact.cpp
index 276151ae..bdcbccb0 100644
--- a/src/CalcManager/Ratpack/fact.cpp
+++ b/src/CalcManager/Ratpack/fact.cpp
@@ -13,7 +13,6 @@
 //     Contains fact(orial) and supporting _gamma functions.
 //
 //-----------------------------------------------------------------------------
-#include "pch.h"
 #include "ratpak.h"
 
 
diff --git a/src/CalcManager/Ratpack/itrans.cpp b/src/CalcManager/Ratpack/itrans.cpp
index 0d2a297e..1521308d 100644
--- a/src/CalcManager/Ratpack/itrans.cpp
+++ b/src/CalcManager/Ratpack/itrans.cpp
@@ -15,7 +15,6 @@
 //  Special Information
 //
 //-----------------------------------------------------------------------------
-#include "pch.h"
 #include "ratpak.h"
 
 
diff --git a/src/CalcManager/Ratpack/itransh.cpp b/src/CalcManager/Ratpack/itransh.cpp
index d6734a1f..50941287 100644
--- a/src/CalcManager/Ratpack/itransh.cpp
+++ b/src/CalcManager/Ratpack/itransh.cpp
@@ -16,7 +16,6 @@
 //
 //
 //-----------------------------------------------------------------------------
-#include "pch.h"
 #include "ratpak.h"
 
 
diff --git a/src/CalcManager/Ratpack/logic.cpp b/src/CalcManager/Ratpack/logic.cpp
index 6444898e..7939ce26 100644
--- a/src/CalcManager/Ratpack/logic.cpp
+++ b/src/CalcManager/Ratpack/logic.cpp
@@ -13,7 +13,6 @@
 //     Contains routines for and, or, xor, not and other support
 //
 //---------------------------------------------------------------------------
-#include "pch.h"
 #include "ratpak.h"
 
 using namespace std;
diff --git a/src/CalcManager/Ratpack/num.cpp b/src/CalcManager/Ratpack/num.cpp
index 2bfa6b89..7b45fea0 100644
--- a/src/CalcManager/Ratpack/num.cpp
+++ b/src/CalcManager/Ratpack/num.cpp
@@ -17,7 +17,8 @@
 //
 //
 //-----------------------------------------------------------------------------
-#include "pch.h"
+#include <list>
+#include <cstring> // for memmove
 #include "ratpak.h"
 
 using namespace std;
diff --git a/src/CalcManager/Ratpack/rat.cpp b/src/CalcManager/Ratpack/rat.cpp
index e101458a..e5a6d254 100644
--- a/src/CalcManager/Ratpack/rat.cpp
+++ b/src/CalcManager/Ratpack/rat.cpp
@@ -16,7 +16,6 @@
 //
 //-----------------------------------------------------------------------------
 
-#include "pch.h"
 #include "ratpak.h"
 
 using namespace std;
diff --git a/src/CalcManager/Ratpack/ratpak.h b/src/CalcManager/Ratpack/ratpak.h
index d9bc11ce..349569a6 100644
--- a/src/CalcManager/Ratpack/ratpak.h
+++ b/src/CalcManager/Ratpack/ratpak.h
@@ -17,7 +17,11 @@
 //
 //-----------------------------------------------------------------------------
 
+#include <algorithm>
+#include <string>
 #include "CalcErr.h"
+#include <cstring> // for memmove
+#include <sal.h> // for SAL
 
 static constexpr uint32_t BASEXPWR = 31L;// Internal log2(BASEX)
 static constexpr uint32_t BASEX = 0x80000000; // Internal radix used in calculations, hope to raise
diff --git a/src/CalcManager/Ratpack/support.cpp b/src/CalcManager/Ratpack/support.cpp
index 22683b4c..1e6a9204 100644
--- a/src/CalcManager/Ratpack/support.cpp
+++ b/src/CalcManager/Ratpack/support.cpp
@@ -18,7 +18,9 @@
 //
 //----------------------------------------------------------------------------
 
-#include "pch.h"
+#include <string>
+#include <cstring> // for memmove
+#include <iostream> // for wostream
 #include "ratpak.h"
 
 using namespace std;
diff --git a/src/CalcManager/Ratpack/trans.cpp b/src/CalcManager/Ratpack/trans.cpp
index 82897564..3706d44d 100644
--- a/src/CalcManager/Ratpack/trans.cpp
+++ b/src/CalcManager/Ratpack/trans.cpp
@@ -14,7 +14,6 @@
 //
 //----------------------------------------------------------------------------
 
-#include "pch.h"
 #include "ratpak.h"
 
 
diff --git a/src/CalcManager/Ratpack/transh.cpp b/src/CalcManager/Ratpack/transh.cpp
index 92a12583..85c27f8b 100644
--- a/src/CalcManager/Ratpack/transh.cpp
+++ b/src/CalcManager/Ratpack/transh.cpp
@@ -14,7 +14,6 @@
 //
 //
 //-----------------------------------------------------------------------------
-#include "pch.h"
 #include "ratpak.h"
 
 
diff --git a/src/CalcManager/UnitConverter.cpp b/src/CalcManager/UnitConverter.cpp
index c1e4cd16..7bfc4817 100644
--- a/src/CalcManager/UnitConverter.cpp
+++ b/src/CalcManager/UnitConverter.cpp
@@ -1,7 +1,9 @@
 // Copyright (c) Microsoft Corporation. All rights reserved.
 // Licensed under the MIT License.
 
-#include "pch.h"
+#include <cassert>
+#include <sstream>
+#include <algorithm> // for std::sort
 #include "Command.h"
 #include "UnitConverter.h"
 
diff --git a/src/CalcManager/UnitConverter.h b/src/CalcManager/UnitConverter.h
index 010216f0..4c77f8aa 100644
--- a/src/CalcManager/UnitConverter.h
+++ b/src/CalcManager/UnitConverter.h
@@ -3,6 +3,12 @@
 
 #pragma once
 
+#include <vector>
+#include <unordered_map>
+#include <ppltasks.h>
+#include <sal.h> // for SAL
+#include <memory> // for std::shared_ptr
+
 namespace UnitConversionManager
 {
     enum class Command;
diff --git a/src/CalcManager/pch.cpp b/src/CalcManager/pch.cpp
index 1da170eb..8ca9987d 100644
--- a/src/CalcManager/pch.cpp
+++ b/src/CalcManager/pch.cpp
@@ -1,4 +1,6 @@
-// Copyright (c) Microsoft Corporation. All rights reserved.
+// Copyright (c) Microsoft Corporation. All rights reserved.
 // Licensed under the MIT License.
 
-#include "pch.h"
+// Intentionally do not include the pch.h here. For projects that don't
+// use precompiled headers, including the header here would force unnecessary compilation.
+// The pch will be included through forced include.
diff --git a/src/CalcManager/pch.h b/src/CalcManager/pch.h
index c5f39b6d..e66e1a38 100644
--- a/src/CalcManager/pch.h
+++ b/src/CalcManager/pch.h
@@ -3,27 +3,20 @@
 
 #pragma once
 
-#ifndef WIN32_LEAN_AND_MEAN
-#define WIN32_LEAN_AND_MEAN
-#endif
+// The CalcManager project should be able to be compiled with or without a precompiled header
+// in - order to support other toolchains besides MSVC. When adding new system headers, make sure
+// that the relevant source file includes all headers it needs, but then also add the system headers
+// here so that MSVC users see the performance benefit.
 
-// Windows headers define min/max macros.
-// Disable it for project code.
-#define NOMINMAX
-
-#include <assert.h>
-#include <windows.h>
-#include <winerror.h>
-#include <sstream>
-#include <iostream>
-#include <iterator>
-#include <string>
-#include <memory>
-#include <vector>
-#include <limits>
-#include <list>
-#include <regex>
-#include <unordered_map>
-#include <intsafe.h>
+#include <algorithm>
 #include <array>
+#include <cassert>
+#include <intsafe.h>
+#include <list>
 #include <ppltasks.h>
+#include <regex>
+#include <sstream>
+#include <string>
+#include <unordered_map>
+#include <vector>
+#include <winerror.h>
diff --git a/src/CalcManager/targetver.h b/src/CalcManager/targetver.h
deleted file mode 100644
index 221efabb..00000000
--- a/src/CalcManager/targetver.h
+++ /dev/null
@@ -1,11 +0,0 @@
-// Copyright (c) Microsoft Corporation. All rights reserved.
-// Licensed under the MIT License.
-
-#pragma once
-
-// Including SDKDDKVer.h defines the highest available Windows platform.
-
-// If you wish to build your application for a previous Windows platform, include WinSDKVer.h and
-// set the _WIN32_WINNT macro to the platform you wish to support before including SDKDDKVer.h.
-
-#include <SDKDDKVer.h>