diff --git a/PCbuild/build.bat b/PCbuild/build.bat
index caed481..713810e 100644
--- a/PCbuild/build.bat
+++ b/PCbuild/build.bat
@@ -53,7 +53,6 @@
 :Run
 setlocal
 set platf=Win32
-set vs_platf=x86
 set conf=Release
 set target=Build
 set dir=%~dp0
@@ -62,10 +61,6 @@
 set kill=
 set do_pgo=
 set pgo_job=-m test --pgo
-set on_64_bit=true
-
-rem This may not be 100% accurate, but close enough.
-if "%ProgramFiles(x86)%"=="" (set on_64_bit=false)
 
 :CheckOpts
 if "%~1"=="-h" goto Usage
@@ -95,18 +90,12 @@
 
 if "%IncludeExternals%"=="true" call "%dir%get_externals.bat"
 
-if "%platf%"=="x64" (
-    if "%on_64_bit%"=="true" (
-        rem This ought to always be correct these days...
-        set vs_platf=amd64
-    ) else (
-        if "%do_pgo%"=="true" (
-            echo.ERROR: Cannot cross-compile with PGO
-            echo.    32bit operating system detected, if this is incorrect,
-            echo.    make sure the ProgramFiles(x86^) environment variable is set
-            exit /b 1
-        )
-        set vs_platf=x86_amd64
+if "%do_pgo%" EQU "true" if "%platf%" EQU "x64" (
+    if "%PROCESSOR_ARCHITEW6432%" NEQ "AMD64" if "%PROCESSOR_ARCHITECTURE%" NEQ "AMD64" (
+        echo.ERROR: Cannot cross-compile with PGO 
+        echo.       32bit operating system detected. Ensure your PROCESSOR_ARCHITECTURE
+        echo.       and PROCESSOR_ARCHITEW6432 environment variables are correct.
+        exit /b 1 
     )
 )
 
@@ -115,7 +104,8 @@
 if not exist "%GIT%" echo Cannot find Git on PATH & set GITProperty=
 
 rem Setup the environment
-call "%dir%env.bat" %vs_platf% >nul
+call "%dir%find_msbuild.bat" %MSBUILD%
+if ERRORLEVEL 1 (echo Cannot locate MSBuild.exe on PATH or as MSBUILD variable & exit /b 2)
 
 if "%kill%"=="true" call :Kill
 
@@ -134,7 +124,7 @@
 goto Build
 :Kill
 echo on
-msbuild "%dir%\pythoncore.vcxproj" /t:KillPython %verbose%^
+%MSBUILD% "%dir%\pythoncore.vcxproj" /t:KillPython %verbose%^
  /p:Configuration=%conf% /p:Platform=%platf%^
  /p:KillPython=true
 
@@ -146,7 +136,7 @@
 rem Passing %1-9 is not the preferred option, but argument parsing in
 rem batch is, shall we say, "lackluster"
 echo on
-msbuild "%dir%pcbuild.proj" /t:%target% %parallel% %verbose%^
+%MSBUILD% "%dir%pcbuild.proj" /t:%target% %parallel% %verbose%^
  /p:Configuration=%conf% /p:Platform=%platf%^
  /p:IncludeExternals=%IncludeExternals%^
  /p:IncludeSSL=%IncludeSSL% /p:IncludeTkinter=%IncludeTkinter%^
@@ -158,4 +148,4 @@
 
 :Version
 rem Display the current build version information
-msbuild "%dir%python.props" /t:ShowVersionInfo /v:m /nologo %1 %2 %3 %4 %5 %6 %7 %8 %9
+%MSBUILD% "%dir%python.props" /t:ShowVersionInfo /v:m /nologo %1 %2 %3 %4 %5 %6 %7 %8 %9
diff --git a/PCbuild/find_msbuild.bat b/PCbuild/find_msbuild.bat
new file mode 100644
index 0000000..1877906
--- /dev/null
+++ b/PCbuild/find_msbuild.bat
@@ -0,0 +1,51 @@
+@rem
+@rem Searches for MSBuild.exe. This is the only tool we need to initiate
+@rem a build, so we no longer search for the full VC toolset.
+@rem
+@rem This file is supposed to modify the state of the caller (specifically
+@rem the MSBUILD variable), so we do not use setlocal or echo, and avoid
+@rem changing any other persistent state.
+@rem
+
+@rem No arguments provided means do full search
+@if '%1' EQU '' goto :begin_search
+
+@rem One argument may be the full path. Use a goto so we don't try to
+@rem parse the next if statement - incorrect quoting in the multi-arg
+@rem case can cause us to break immediately.
+@if '%2' EQU '' goto :one_arg
+
+@rem Entire command line may represent the full path if quoting failed.
+@if exist "%*" (set MSBUILD="%*") & (set _Py_MSBuild_Source=environment) & goto :found
+@goto :begin_search
+
+:one_arg
+@if exist "%~1" (set MSBUILD="%~1") & (set _Py_MSBuild_Source=environment) & goto :found
+
+:begin_search
+@set MSBUILD=
+
+@rem If msbuild.exe is on the PATH, assume that the user wants that one.
+@where msbuild > "%TEMP%\msbuild.loc" 2> nul && set /P MSBUILD= < "%TEMP%\msbuild.loc" & del "%TEMP%\msbuild.loc"
+@if exist "%MSBUILD%" set MSBUILD="%MSBUILD%" & (set _Py_MSBuild_Source=PATH) & goto :found
+
+@rem VS 2017 sets exactly one install as the "main" install, so we may find MSBuild in there.
+@reg query "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\VisualStudio\SxS\VS7" /v 15.0 /reg:32 >nul 2>nul
+@if NOT ERRORLEVEL 1 @for /F "tokens=1,2*" %%i in ('reg query "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\VisualStudio\SxS\VS7" /v 15.0 /reg:32') DO @(
+    @if "%%i"=="15.0" @if exist "%%k\MSBuild\15.0\Bin\msbuild.exe" @(set MSBUILD="%%k\MSBuild\15.0\Bin\msbuild.exe")
+)
+@if exist %MSBUILD% (set _Py_MSBuild_Source=Visual Studio 2017 registry) & goto :found
+
+@rem VS 2015 and earlier register MSBuild separately, so we can find it.
+@reg query "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MSBuild\ToolsVersions\14.0" /v MSBuildToolsPath /reg:32 >nul 2>nul
+@if NOT ERRORLEVEL 1 @for /F "tokens=1,2*" %%i in ('reg query "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MSBuild\ToolsVersions\14.0" /v MSBuildToolsPath /reg:32') DO @(
+    @if "%%i"=="MSBuildToolsPath" @if exist "%%k\msbuild.exe" @(set MSBUILD="%%k\msbuild.exe")
+)
+@if exist %MSBUILD% (set _Py_MSBuild_Source=registry) & goto :found
+
+
+@exit /b 1
+
+:found
+@echo Using %MSBUILD% (found in the %_Py_MSBuild_Source%)
+@set _Py_MSBuild_Source=
diff --git a/PCbuild/python.vcxproj b/PCbuild/python.vcxproj
index 807213f..2786ac2 100644
--- a/PCbuild/python.vcxproj
+++ b/PCbuild/python.vcxproj
@@ -83,7 +83,7 @@
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
   <ImportGroup Label="ExtensionTargets">
   </ImportGroup>
-  <Target Name="ValidateUcrtbase" AfterTargets="AfterBuild">
+  <Target Name="ValidateUcrtbase" AfterTargets="AfterBuild" Condition="$(Configuration) != 'PGInstrument'">
     <PropertyGroup>
       <UcrtName>ucrtbase</UcrtName>
       <UcrtName Condition="'$(Configuration)' == 'Debug'">ucrtbased</UcrtName>
@@ -94,6 +94,8 @@
   </Target>
   <Target Name="GeneratePythonBat" AfterTargets="AfterBuild">
     <PropertyGroup>
+      <_PGOPath Condition="$(Configuration) == 'PGInstrument' and $(Platform) == 'Win32'">@set PATH=%PATH%%3B$(VCInstallDir)bin</_PGOPath>
+      <_PGOPath Condition="$(Configuration) == 'PGInstrument' and $(Platform) == 'x64'">@set PATH=%PATH%%3B$(VCInstallDir)bin\amd64</_PGOPath>
       <_Content>@rem This script invokes the most recently built Python with all arguments
 @rem passed through to the interpreter.  This file is generated by the
 @rem build process and any changes *will* be thrown away by the next
@@ -103,6 +105,7 @@
 @echo Running $(Configuration)^|$(Platform) interpreter...
 @setlocal
 @set PYTHONHOME=$(PySourcePath)
+$(_PGOPath)
 @"$(OutDir)python$(PyDebugExt).exe" %*
 </_Content>
       <_ExistingContent Condition="Exists('$(PySourcePath)python.bat')">$([System.IO.File]::ReadAllText('$(PySourcePath)python.bat'))</_ExistingContent>