Windows - Photoshop CC or newer

You use Photoshop CC or newer on Windows.

64 bit or 32 bit?

Photoshop CC comes in two flavours, 64 bit and 32 bit. If you use a 32bit version of Windows, you only have the 32bit version, choose 32 bit below.

If you use a 64 bit version of Windows, you may have both 64 bit and 32 bit versions of Photoshop. You can check if your Photoshop is 64-bit or 32-bit in the System Info. From the Photoshop Help menu, choose "System Info...". The top-most line shows the Photoshop version. If it has x64 at the end, you are using 64-bit and then you also need 64-bit plug-ins. If this line ends in x32 you are using 32-bit Photoshop.

Which one do you use?