More build instructions

Sandboxie/ReadMe.md

@@ -1,11 +1,21 @@
 ## Sandboxie Build Instructions
 
-Please note: there is another [ReadMe.md](./install/ReadMe.md) file in the [\install](./install/) folder that explains how to create the Sandboxie installers.
-
-1) Sandboxie builds under MS Visual Studio 2019.
-2) Install the Windows Driver Kit (WDK) for Windows 10, version 2004:
+Please note: there is another [ReadMe.md](./install/ReadMe.md) file in the [\install](./install/) folder that explains how to create the Sandboxie installers.  
+
+Sandboxie builds under MS Visual Studio 2019.  
+1) Acquire [Visual Studio 2019](https://visualstudio.microsoft.com/vs/older-downloads/#visual-studio-2019-and-other-products)
+2) In the Visual Studio Installer, tick "Desktop development with C++"
+	- This will install all needed components to build, including the Windows 10 SDK (10.0.19041)
+3) If you need to build for other platforms, install the corresponding components <!-- If I can get it to work! -->
+	- MSVC v142 - VS 2019 C++ {architecture} build tools (Latest)
+	- MFC for latest v142 build tools {architecture}
+4) Install the Windows Driver Kit (WDK) for Windows 10, version 2004 (10.0.19041):
 	https://go.microsoft.com/fwlink/?linkid=2128854
-3) The VS Solution File, Sandbox.sln, is in the source code root. Open this SLN in Visual Studio.
+5) The VS Solution File, Sandbox.sln, is in the source code root. Open this SLN in Visual Studio.
+6) If the WDK Extension doesn't install automatically, install it (can be found in <Windows Kits directory>\10\Vsix\VS2019)
+7) If you have a more recent Windows SDK version installed, retarget the solution to 10.0.19041
+	- This is for example necessary if VS2022 is also installed with the default desktop C++ components
+8) To compile for x64, it's necessary to first compile `core/LowLevel` for Win32
 
 ### Source Projects (in alphabetical order)