The Microsoft Java Virtual Machine (MSJVM) is a program that allows Java programs and applets (small java programs) to run on your computer. Java is a programming language that allows developers to write their program once, and it will run on any computer that has a Java Virtual Machine. Without this capability a program would have to be written for each computer - one version for Windows, one version for Apples, one version for UNIX... a royal pain for developers.

There are a lot of games and other interactive programs that you can use online, and Java is the program language that a lot of them are written in. Microsoft licensed the Java technology from Sun Microsystems and has included it in every version of Windows since Windows 95.

To find out which version of Java you are using, go to www.javatester.org for a quick check.

Due to a series of lawsuits over how Microsoft was changing the JVM, Microsoft decided to stop including it in 2001, but included it again in 2002 after a lot of customers complained. One of the problems with the Microsoft version is that it opened up a lot of security holes, and there have been numerous patches for the program over the years. In spite of this, there are still some holes that allow programs to take over your Internet Explorer browser by hijacking your home page, adding links (usually to pornography sites) to your Favorites, and taking over your search capabilities by redirecting you to a particular search page.

Microsoft has dropped support for MSJVM as of October 1st, 2004, so it is a security risk just waiting for an exploit to hit it. You can uninstall MSJVM in Windows XP by following the directions here.

After you have uninstalled the MS version, you will need to install the Sun Java software to replace MSJVM, and a free and painless download is available here.

If the uninstall directions don't work on your computer, install the Sun Java software. Then check your Internet Explorer Options (Tools | Internet Options | Advanced) to make sure that the Sun Java is checked and the MSJVM is unchecked.

Even if you do not have problems with hijacked homepages, et al., you should uninstall the Microsoft version and install the Sun Java software. With no updates coming from Microsoft, any more holes that are discovered will open your computer to attack, and that is NEVER a good thing!