The recommendation is install JDK 64-bit if your Windows is 64-bit operating system installed.
NOTE: If your system is of Windows 32-bit operating system then you should install JDK 32 bit and if your system is of Windows 64 bit operating system then you have a choice either you can install JDK 64 bit or JDK 32-bit in your system. The JDK includes tools useful for developing and testing programs written in the Java programming language and running on the Java TM platform. Here we are going to download 64-bit JDK 1.8 and install it on the Windows 10 64-bit Operating System. The JDK is a development environment for building applications using the Java programming language.
How to Download JDK 8 and Install it on Windows 10?.