The Java Platform was designed to allow applications to run on different hardware stacks and operating systems without changes. Java is available on Microsoft Windows in 64 and 32 bit versions, allowing users to get the appropriate version for their system. Users can even run both side-by-side for 64 bit operating systems.
End-users should visit Java.com and click the Free Java Download link. The site will auto-detect the web browser and serve the appropriate download.
For an explanation of how the website makes that determination, please see "Which Java download should I choose for my 64-bit Windows operating system.”
Users that run Applets and Web Start applications through web browsers should choose the version of Java that matches their web browser. Generally speaking, 64 bit browsers run only 64 bit plugins and 32 bit browsers run only 32 bit plugins.
As of mid-September 2014:
When you have a choice, there are many benefits to choosing 64 bit.
Most users in managed environments should choose which browsers and runtimes to use – managing one installation is easier than two.
If you cannot choose or do not know which you should choose, you can run both the 64 bit and 32 bit Java on the same computer. The relevant plugins will be available for both browser types, and system-wide configurations like Deployment Rule Sets will automatically apply to both
When running both 64 and 32 bit versions on a Windows client, there will be two installations:
Any configuration changes made to the runtime itself (e.g. inside the JRE folder) must be made to both Java installations: “Program Files” as well as “Program Files (x86).”
Advanced Windows users that run local Java programs may want to check the following attributes as well:
In the above examples on my system, I have chosen 64 bit each time. To do that, I also changed my browsers around to use the 64 bit version as the default and installed a separate 32 bit Java specifically for my Firefox client.
The 64 and 32 bit Java installations are separate from each-other. If you choose to use both, please plan to upgrade both at each scheduled Critical Patch Update or as prompted.