I have written in the past that you really only need to have one version of Java installed on your machine – the latest. Unfortunately the Java installer does not remove your outdated versions when upgrading to the new version, which leaves the older and probably more vunerable releases installed.
Rather than uninstalling them manually, check out this post which references a tool to automatically do this for you. The tool is free and can save you quite a bit of time if you have 5 or more older versions of Java installed… which is actually quite common.

Like what you read?
If so, please join over 28,000 people who receive our exclusive weekly newsletter and computer tips, and get FREE COPIES of 5 eBooks we created, as our gift to you for subscribing. Just enter your name and email below:



Great tip, thanks!
Also, a question: does the same rule (only need one version) apply to the .NET framework service packs? I have several installed, for example, .NET framework 2.0 SP2, and .NET framework 3.0, SP2.
Also, this isn’t really directly related, but is there a utility to clean out registry entries pertaining to installed applications that aren’t really there? I imported some entries from one computer to my laptop, as I needed them for an application I had copied over, and accidentally ended up with all of the uninstallation entries from that computer, so my uninstallation utility (Revo Uninstaller) incorrectly lists applications I don’t really have installed.
I’ve tried CCleaner, but it didn’t remove the entries.
Ah, disregard the first bit, I didn’t notice your posts regarding .NET until after I commented.
Vertimyst, with regard to “installed applications that aren’t really there”, it might help to understand where the list of “installed programs” comes from.
The Windows Control Panel module “Add or Remove Programs” gets its program list from a specific location in the Windows Registry. I wouldn’t be at all surprised if Revo UnInstaller got its information from the same place, but I don’t use Revo so I can’t say for sure how it does its job.
For more information go to my blog and scroll down to the title:
Understanding & Troubleshooting the “Add or Remove Programs” Applet
Once you know how things work its quite possible to do some manual cleaning up.
– Bill Hely
– Author: “The Hacker’s Nightmare”
– “How to keep hackers, worms & other germs out of your PC”
– BLOG: http://ComputerAndOnlineSecurity.com
There are two potential problems with uninstalling instances of Java when there are multiple instances discovered on the PC.
Problem #1: Some applications expect to find a specific version of Java and will return errors even if a later version is installed in place of the original. The author of the article you quoted states: “Sun does this just in case some old applications won’t work with the latest Java version. In my experience, this is a rarity.” Nevertheless it is still quite possible to encounter such a situation.
Problem #2: Some applications expect to find the Java installation in a specific location, usually a subfolder of the program installation itself.
While not common, I have encountered both of these circumstances on more than one occasion in the past. In both cases the program installation routine installs its own copy of Java, rather than looking for an existing instance or requiring that Java be installed separately.
I’m not a Java programmer, but I suspect that these are circumstances that shouldn’t be allowed to occur. In other words, they are the result of carelessness or poor design.
Whatever the reason it’s worth bearing in mind that removal/updating of existing Java instances just might have unforeseen side-effects, so be prepared to back-pedal if necessary.
– Bill Hely
– Author: “The Hacker’s Nightmare”
– “How to keep hackers, worms & other germs out of your PC”
– BLOG: http://ComputerAndOnlineSecurity.com