diff --git a/build/at0.vcxproj b/build/at0.vcxproj
index 7aa0c6b18..90da14fd7 100644
--- a/build/at0.vcxproj
+++ b/build/at0.vcxproj
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<Project DefaultTargets="Build" ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+<Project DefaultTargets="Build" ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <ItemGroup Label="ProjectConfigurations">
     <ProjectConfiguration Include="Debug|Win32">
       <Configuration>Debug</Configuration>
@@ -13,15 +13,18 @@
   <PropertyGroup Label="Globals">
     <ProjectGuid>{4E407F68-5E64-4239-B1A0-15292AFAFCDE}</ProjectGuid>
     <RootNamespace>at0</RootNamespace>
+    <WindowsTargetPlatformVersion>10.0.19041.0</WindowsTargetPlatformVersion>
   </PropertyGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.Default.props" />
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'" Label="Configuration">
     <ConfigurationType>Application</ConfigurationType>
     <UseOfMfc>false</UseOfMfc>
+    <PlatformToolset>v141</PlatformToolset>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'" Label="Configuration">
     <ConfigurationType>Application</ConfigurationType>
     <UseOfMfc>false</UseOfMfc>
+    <PlatformToolset>v141</PlatformToolset>
   </PropertyGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
   <ImportGroup Label="ExtensionSettings">
@@ -116,7 +119,6 @@
       <AssemblerListingLocation>.\..\debug/</AssemblerListingLocation>
       <ObjectFileName>.\..\debug/</ObjectFileName>
       <ProgramDataBaseFileName>.\..\debug/</ProgramDataBaseFileName>
-      
       <WarningLevel>Level3</WarningLevel>
       <SuppressStartupBanner>true</SuppressStartupBanner>
       <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
diff --git a/build/at1.vcxproj b/build/at1.vcxproj
index a26d904f5..46c7cf96f 100644
--- a/build/at1.vcxproj
+++ b/build/at1.vcxproj
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<Project DefaultTargets="Build" ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+<Project DefaultTargets="Build" ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <ItemGroup Label="ProjectConfigurations">
     <ProjectConfiguration Include="Debug|Win32">
       <Configuration>Debug</Configuration>
@@ -13,15 +13,18 @@
   <PropertyGroup Label="Globals">
     <ProjectGuid>{FFE1611E-E146-4B8E-AB51-8512592D4519}</ProjectGuid>
     <RootNamespace>at1</RootNamespace>
+    <WindowsTargetPlatformVersion>10.0.19041.0</WindowsTargetPlatformVersion>
   </PropertyGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.Default.props" />
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'" Label="Configuration">
     <ConfigurationType>Application</ConfigurationType>
     <UseOfMfc>false</UseOfMfc>
+    <PlatformToolset>v141</PlatformToolset>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'" Label="Configuration">
     <ConfigurationType>Application</ConfigurationType>
     <UseOfMfc>false</UseOfMfc>
+    <PlatformToolset>v141</PlatformToolset>
   </PropertyGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
   <ImportGroup Label="ExtensionSettings">
@@ -116,7 +119,6 @@
       <AssemblerListingLocation>.\..\debug/</AssemblerListingLocation>
       <ObjectFileName>.\..\debug/</ObjectFileName>
       <ProgramDataBaseFileName>.\..\debug/</ProgramDataBaseFileName>
-      
       <WarningLevel>Level3</WarningLevel>
       <SuppressStartupBanner>true</SuppressStartupBanner>
       <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
diff --git a/build/at2.vcxproj b/build/at2.vcxproj
index c1311c161..54db38a17 100644
--- a/build/at2.vcxproj
+++ b/build/at2.vcxproj
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<Project DefaultTargets="Build" ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+<Project DefaultTargets="Build" ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <ItemGroup Label="ProjectConfigurations">
     <ProjectConfiguration Include="Debug|Win32">
       <Configuration>Debug</Configuration>
@@ -13,15 +13,18 @@
   <PropertyGroup Label="Globals">
     <ProjectGuid>{81CDB10D-42C9-4FBC-92F2-6A703365860D}</ProjectGuid>
     <RootNamespace>at2</RootNamespace>
+    <WindowsTargetPlatformVersion>10.0.19041.0</WindowsTargetPlatformVersion>
   </PropertyGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.Default.props" />
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'" Label="Configuration">
     <ConfigurationType>Application</ConfigurationType>
     <UseOfMfc>false</UseOfMfc>
+    <PlatformToolset>v141</PlatformToolset>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'" Label="Configuration">
     <ConfigurationType>Application</ConfigurationType>
     <UseOfMfc>false</UseOfMfc>
+    <PlatformToolset>v141</PlatformToolset>
   </PropertyGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
   <ImportGroup Label="ExtensionSettings">
@@ -65,7 +68,6 @@
       <AssemblerListingLocation>.\..\debug/</AssemblerListingLocation>
       <ObjectFileName>.\..\debug/</ObjectFileName>
       <ProgramDataBaseFileName>.\..\debug/</ProgramDataBaseFileName>
-      
       <WarningLevel>Level3</WarningLevel>
       <SuppressStartupBanner>true</SuppressStartupBanner>
       <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
diff --git a/build/at3.vcxproj b/build/at3.vcxproj
index 9529205ed..4f9117aef 100644
--- a/build/at3.vcxproj
+++ b/build/at3.vcxproj
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<Project DefaultTargets="Build" ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+<Project DefaultTargets="Build" ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <ItemGroup Label="ProjectConfigurations">
     <ProjectConfiguration Include="Debug|Win32">
       <Configuration>Debug</Configuration>
@@ -13,15 +13,18 @@
   <PropertyGroup Label="Globals">
     <ProjectGuid>{FDE55126-89F2-4496-A809-D5B0D86677BE}</ProjectGuid>
     <RootNamespace>at3</RootNamespace>
+    <WindowsTargetPlatformVersion>10.0.19041.0</WindowsTargetPlatformVersion>
   </PropertyGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.Default.props" />
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'" Label="Configuration">
     <ConfigurationType>Application</ConfigurationType>
     <UseOfMfc>false</UseOfMfc>
+    <PlatformToolset>v141</PlatformToolset>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'" Label="Configuration">
     <ConfigurationType>Application</ConfigurationType>
     <UseOfMfc>false</UseOfMfc>
+    <PlatformToolset>v141</PlatformToolset>
   </PropertyGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
   <ImportGroup Label="ExtensionSettings">
@@ -116,7 +119,6 @@
       <AssemblerListingLocation>.\..\debug/</AssemblerListingLocation>
       <ObjectFileName>.\..\debug/</ObjectFileName>
       <ProgramDataBaseFileName>.\..\debug/</ProgramDataBaseFileName>
-      
       <WarningLevel>Level3</WarningLevel>
       <SuppressStartupBanner>true</SuppressStartupBanner>
       <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
diff --git a/build/at4.vcxproj b/build/at4.vcxproj
index 2358624a5..7b39f1610 100644
--- a/build/at4.vcxproj
+++ b/build/at4.vcxproj
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<Project DefaultTargets="Build" ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+<Project DefaultTargets="Build" ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <ItemGroup Label="ProjectConfigurations">
     <ProjectConfiguration Include="Debug|Win32">
       <Configuration>Debug</Configuration>
@@ -13,15 +13,18 @@
   <PropertyGroup Label="Globals">
     <ProjectGuid>{4B594D3C-2439-4BE9-94BC-B055A6C2D8BE}</ProjectGuid>
     <RootNamespace>at4</RootNamespace>
+    <WindowsTargetPlatformVersion>10.0.19041.0</WindowsTargetPlatformVersion>
   </PropertyGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.Default.props" />
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'" Label="Configuration">
     <ConfigurationType>Application</ConfigurationType>
     <UseOfMfc>false</UseOfMfc>
+    <PlatformToolset>v141</PlatformToolset>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'" Label="Configuration">
     <ConfigurationType>Application</ConfigurationType>
     <UseOfMfc>false</UseOfMfc>
+    <PlatformToolset>v141</PlatformToolset>
   </PropertyGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
   <ImportGroup Label="ExtensionSettings">
@@ -116,7 +119,6 @@
       <AssemblerListingLocation>.\..\debug/</AssemblerListingLocation>
       <ObjectFileName>.\..\debug/</ObjectFileName>
       <ProgramDataBaseFileName>.\..\debug/</ProgramDataBaseFileName>
-      
       <WarningLevel>Level3</WarningLevel>
       <SuppressStartupBanner>true</SuppressStartupBanner>
       <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
diff --git a/build/at5.vcxproj b/build/at5.vcxproj
index f23008e27..9f81a91c4 100644
--- a/build/at5.vcxproj
+++ b/build/at5.vcxproj
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<Project DefaultTargets="Build" ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+<Project DefaultTargets="Build" ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <ItemGroup Label="ProjectConfigurations">
     <ProjectConfiguration Include="Debug|Win32">
       <Configuration>Debug</Configuration>
@@ -13,15 +13,18 @@
   <PropertyGroup Label="Globals">
     <ProjectGuid>{4E62A07A-805A-4DC5-A880-022CF5142D20}</ProjectGuid>
     <RootNamespace>at5</RootNamespace>
+    <WindowsTargetPlatformVersion>10.0.19041.0</WindowsTargetPlatformVersion>
   </PropertyGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.Default.props" />
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'" Label="Configuration">
     <ConfigurationType>Application</ConfigurationType>
     <UseOfMfc>false</UseOfMfc>
+    <PlatformToolset>v141</PlatformToolset>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'" Label="Configuration">
     <ConfigurationType>Application</ConfigurationType>
     <UseOfMfc>false</UseOfMfc>
+    <PlatformToolset>v141</PlatformToolset>
   </PropertyGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
   <ImportGroup Label="ExtensionSettings">
@@ -116,7 +119,6 @@
       <AssemblerListingLocation>.\..\debug/</AssemblerListingLocation>
       <ObjectFileName>.\..\debug/</ObjectFileName>
       <ProgramDataBaseFileName>.\..\debug/</ProgramDataBaseFileName>
-      
       <WarningLevel>Level3</WarningLevel>
       <SuppressStartupBanner>true</SuppressStartupBanner>
       <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
diff --git a/build/at6.vcxproj b/build/at6.vcxproj
index 0bfe9e19e..7ad829e76 100644
--- a/build/at6.vcxproj
+++ b/build/at6.vcxproj
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<Project DefaultTargets="Build" ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+<Project DefaultTargets="Build" ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <ItemGroup Label="ProjectConfigurations">
     <ProjectConfiguration Include="Debug|Win32">
       <Configuration>Debug</Configuration>
@@ -13,15 +13,18 @@
   <PropertyGroup Label="Globals">
     <ProjectGuid>{93652727-3417-46FA-BC6D-5497DB922D8E}</ProjectGuid>
     <RootNamespace>at6</RootNamespace>
+    <WindowsTargetPlatformVersion>10.0.19041.0</WindowsTargetPlatformVersion>
   </PropertyGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.Default.props" />
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'" Label="Configuration">
     <ConfigurationType>Application</ConfigurationType>
     <UseOfMfc>false</UseOfMfc>
+    <PlatformToolset>v141</PlatformToolset>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'" Label="Configuration">
     <ConfigurationType>Application</ConfigurationType>
     <UseOfMfc>false</UseOfMfc>
+    <PlatformToolset>v141</PlatformToolset>
   </PropertyGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
   <ImportGroup Label="ExtensionSettings">
@@ -66,7 +69,6 @@
       <AssemblerListingLocation>.\..\debug/</AssemblerListingLocation>
       <ObjectFileName>.\..\debug/</ObjectFileName>
       <ProgramDataBaseFileName>.\..\debug/</ProgramDataBaseFileName>
-      
       <WarningLevel>Level3</WarningLevel>
       <SuppressStartupBanner>true</SuppressStartupBanner>
       <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
@@ -120,7 +122,6 @@
       <RuntimeLibrary>MultiThreaded</RuntimeLibrary>
       <FunctionLevelLinking>true</FunctionLevelLinking>
       <PrecompiledHeaderOutputFile>$(IntDir)$(TargetName).pch</PrecompiledHeaderOutputFile>
-      
       <WarningLevel>Level3</WarningLevel>
       <SuppressStartupBanner>true</SuppressStartupBanner>
       <MultiProcessorCompilation>true</MultiProcessorCompilation>
diff --git a/build/at7.vcxproj b/build/at7.vcxproj
index 41acea0a0..4c5996e18 100644
--- a/build/at7.vcxproj
+++ b/build/at7.vcxproj
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<Project DefaultTargets="Build" ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+<Project DefaultTargets="Build" ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <ItemGroup Label="ProjectConfigurations">
     <ProjectConfiguration Include="Debug|Win32">
       <Configuration>Debug</Configuration>
@@ -13,15 +13,18 @@
   <PropertyGroup Label="Globals">
     <ProjectGuid>{7E5C5180-35F2-4B7E-8C28-A09DD29028CA}</ProjectGuid>
     <RootNamespace>at7</RootNamespace>
+    <WindowsTargetPlatformVersion>10.0.19041.0</WindowsTargetPlatformVersion>
   </PropertyGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.Default.props" />
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'" Label="Configuration">
     <ConfigurationType>Application</ConfigurationType>
     <UseOfMfc>false</UseOfMfc>
+    <PlatformToolset>v141</PlatformToolset>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'" Label="Configuration">
     <ConfigurationType>Application</ConfigurationType>
     <UseOfMfc>false</UseOfMfc>
+    <PlatformToolset>v141</PlatformToolset>
   </PropertyGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
   <ImportGroup Label="ExtensionSettings">
@@ -116,7 +119,6 @@
       <AssemblerListingLocation>.\..\debug/</AssemblerListingLocation>
       <ObjectFileName>.\..\debug/</ObjectFileName>
       <ProgramDataBaseFileName>.\..\debug/</ProgramDataBaseFileName>
-      
       <WarningLevel>Level3</WarningLevel>
       <SuppressStartupBanner>true</SuppressStartupBanner>
       <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
diff --git a/build/at8.vcxproj b/build/at8.vcxproj
index c00c85e0b..6656864f2 100644
--- a/build/at8.vcxproj
+++ b/build/at8.vcxproj
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<Project DefaultTargets="Build" ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+<Project DefaultTargets="Build" ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <ItemGroup Label="ProjectConfigurations">
     <ProjectConfiguration Include="Debug|Win32">
       <Configuration>Debug</Configuration>
@@ -13,15 +13,18 @@
   <PropertyGroup Label="Globals">
     <ProjectGuid>{746AC55F-2085-49F3-BE67-AA8C190E2537}</ProjectGuid>
     <RootNamespace>at8</RootNamespace>
+    <WindowsTargetPlatformVersion>10.0.19041.0</WindowsTargetPlatformVersion>
   </PropertyGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.Default.props" />
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'" Label="Configuration">
     <ConfigurationType>Application</ConfigurationType>
     <UseOfMfc>false</UseOfMfc>
+    <PlatformToolset>v141</PlatformToolset>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'" Label="Configuration">
     <ConfigurationType>Application</ConfigurationType>
     <UseOfMfc>false</UseOfMfc>
+    <PlatformToolset>v141</PlatformToolset>
   </PropertyGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
   <ImportGroup Label="ExtensionSettings">
@@ -65,7 +68,6 @@
       <AssemblerListingLocation>.\..\debug/</AssemblerListingLocation>
       <ObjectFileName>.\..\debug/</ObjectFileName>
       <ProgramDataBaseFileName>.\..\debug/</ProgramDataBaseFileName>
-      
       <WarningLevel>Level3</WarningLevel>
       <SuppressStartupBanner>true</SuppressStartupBanner>
       <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
diff --git a/build/at9.vcxproj b/build/at9.vcxproj
index f25400e5b..be2507ce2 100644
--- a/build/at9.vcxproj
+++ b/build/at9.vcxproj
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<Project DefaultTargets="Build" ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+<Project DefaultTargets="Build" ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <ItemGroup Label="ProjectConfigurations">
     <ProjectConfiguration Include="Debug|Win32">
       <Configuration>Debug</Configuration>
@@ -13,15 +13,18 @@
   <PropertyGroup Label="Globals">
     <ProjectGuid>{2FB5C989-0352-4BB3-9A62-68AA6B5FA3C9}</ProjectGuid>
     <RootNamespace>at9</RootNamespace>
+    <WindowsTargetPlatformVersion>10.0.19041.0</WindowsTargetPlatformVersion>
   </PropertyGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.Default.props" />
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'" Label="Configuration">
     <ConfigurationType>Application</ConfigurationType>
     <UseOfMfc>false</UseOfMfc>
+    <PlatformToolset>v141</PlatformToolset>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'" Label="Configuration">
     <ConfigurationType>Application</ConfigurationType>
     <UseOfMfc>false</UseOfMfc>
+    <PlatformToolset>v141</PlatformToolset>
   </PropertyGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
   <ImportGroup Label="ExtensionSettings">
@@ -117,7 +120,6 @@
       <AssemblerListingLocation>.\..\debug/</AssemblerListingLocation>
       <ObjectFileName>.\..\debug/</ObjectFileName>
       <ProgramDataBaseFileName>.\..\debug/</ProgramDataBaseFileName>
-      
       <WarningLevel>Level3</WarningLevel>
       <SuppressStartupBanner>true</SuppressStartupBanner>
       <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
diff --git a/build/at_forms.vcxproj b/build/at_forms.vcxproj
index 16985d491..127d5430b 100644
--- a/build/at_forms.vcxproj
+++ b/build/at_forms.vcxproj
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<Project DefaultTargets="Build" ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+<Project DefaultTargets="Build" ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <ItemGroup Label="ProjectConfigurations">
     <ProjectConfiguration Include="Debug|Win32">
       <Configuration>Debug</Configuration>
@@ -13,17 +13,20 @@
   <PropertyGroup Label="Globals">
     <ProjectGuid>{C7838AB2-87D7-4A47-817D-ED16B604559A}</ProjectGuid>
     <RootNamespace>at_forms</RootNamespace>
+    <WindowsTargetPlatformVersion>10.0.19041.0</WindowsTargetPlatformVersion>
   </PropertyGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.Default.props" />
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'" Label="Configuration">
     <ConfigurationType>Application</ConfigurationType>
     <UseOfMfc>false</UseOfMfc>
     <CharacterSet>MultiByte</CharacterSet>
+    <PlatformToolset>v141</PlatformToolset>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'" Label="Configuration">
     <ConfigurationType>Application</ConfigurationType>
     <UseOfMfc>false</UseOfMfc>
     <CharacterSet>MultiByte</CharacterSet>
+    <PlatformToolset>v141</PlatformToolset>
   </PropertyGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
   <ImportGroup Label="ExtensionSettings">
diff --git a/build/at_masktab.vcxproj b/build/at_masktab.vcxproj
index 90f4ad7bb..0df5b342d 100644
--- a/build/at_masktab.vcxproj
+++ b/build/at_masktab.vcxproj
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<Project DefaultTargets="Build" ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+<Project DefaultTargets="Build" ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <ItemGroup Label="ProjectConfigurations">
     <ProjectConfiguration Include="Debug|Win32">
       <Configuration>Debug</Configuration>
@@ -13,17 +13,20 @@
   <PropertyGroup Label="Globals">
     <ProjectGuid>{D481396E-6095-45CA-B06D-7E163B50D596}</ProjectGuid>
     <RootNamespace>at_masktab</RootNamespace>
+    <WindowsTargetPlatformVersion>10.0.19041.0</WindowsTargetPlatformVersion>
   </PropertyGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.Default.props" />
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'" Label="Configuration">
     <ConfigurationType>Application</ConfigurationType>
     <UseOfMfc>false</UseOfMfc>
     <CharacterSet>MultiByte</CharacterSet>
+    <PlatformToolset>v141</PlatformToolset>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'" Label="Configuration">
     <ConfigurationType>Application</ConfigurationType>
     <UseOfMfc>false</UseOfMfc>
     <CharacterSet>MultiByte</CharacterSet>
+    <PlatformToolset>v141</PlatformToolset>
   </PropertyGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
   <ImportGroup Label="ExtensionSettings">