Download and save the Java installer for reuse.
Do I need Java?
What is Java technology and why do I need it?
Why should I remove older versions of Java from my system?
Determine if you have Java and which version.
If you do have Java installed and active then you will most likely be aware of it thanks to the pop-up messages you get when a new version becomes available (unless you have manually turned off auto-updates). If you are in doubt then the Official Java test page and the Verify Java Version pages can tell you if Java is installed and active and which version is in use. There are also a few third-party website that do Java testing and you can find a couple of links at the foot of this page.
Alternatively for Windows you can look in Control Panel to see if the Java coffee cup icon is there and if so double-click to open the Java Control Panel from where you can view version and build information. Another method is to look at your installed programs in Programs and Features (Add/Remove Programs in XP), where you should see both version and build update numbers displayed. Or you can look in your browser at the installed plug-ins or add-ons to see if Java is listed there. Or you can even just look in the Program Files folder of Windows to see if there is a folder in there called Java.
Pay attention during install as Oracle are not above trying to sneak some unwanted extras onto your system. The standalone installer is not as bad at the moment as the online install or update, but that could change so watch out for any options offering tool bars or virus scanners or the like as the default will be to include them, so you need to be observant enough to un-check the not so obvious tick box. If you can get your hands on the .msi installer as opposed to the .exe installer then you can avoid the dangers of any extras. See the section below about retrieving left-over installers.
A close look at how Oracle installs deceptive software with their Java updates: - by Ed Bott at ZDNet
The real tech guys out there have the option of excluding the entire update component from even being installed by doing a command line silent install. For the rest of us there is a round-about way to get our hands on an installer that does not include the updater. See the next paragraph about .msi installers.
One useful aspect of installing from this .msi installer is that it does not include the Auto-Update component of the Java package and will even leave out the entire update tab from the Java Control Panel. The auto-update function has its own separate .msi installer which you should find inside another folder called AU that will also be inside the Sun/Java folder. If you do want the auto-update feature then install it in the same way, after of course you have installed the main Java update.
If you can’t find the .msi files on your system after doing an auto-update, then a full manual install from the downloaded standalone .exe installer seems to always do the trick and leave the .msi installer files in place, (at least for the Java versions tested up to the writing of this article - jre1.7.0_11).
Official Java test page
Verify Java Version
The Java Control Panel
The Windows Control Panel
What is Java and why do I need it?
Why should I remove older versions of Java?
Which Version for 64-bit Windows?
Oracle installs deceptive software with updates
Configure Java Automatic Update
The Windows msconfig utility
Codestuff's Starter App
Microsoft's Autoruns utility
Doing a Java silent install
What is Java Quick Starter (JQS)?
Duke - the Java Mascot.
Who Knew!? ..... http://www.oracle.com/us/technologies/java/duke-424174.html