Hi Mary,

The latest version of Java is always the recommended version as it contains feature updates, vulnerability fixes and performance improvements to previous versions.

You can find the Java version you are using by the following methods:

Method 1. Starting with Java 7 Update 40, you can find the Java version through the Windows Start menu.

1. Launch the Windows Start menu
2. Click on Programs
3. Find the Java program listing
4. Click About Java to see the Java version

Method 2: You can determine which version of the JDK is the default by typing java -version in a Terminal window.
If the installed version is 7u55, you will see a string that includes the text 1.7.0_55.
For example:
java -version
java version "1.7.0_55"

In order to remove previous versions of Java and use the latest one, you can use the below methods.

Method 1: Enable the latest installed version of Java in the Java Control Panel

1. In the Java Control Panel, click on the Java tab.
2. Click View to display the Java Runtime Environment Settings
3. Verify that the latest Java Runtime version is enabled by checking the Enabled box.
   
   
4. Click OK to save settings
5. Click OK in Java Control Panel window to confirm changes and close the window.

Method 2: Use Java uninstaller tool
The Java Uninstall tool helps you improve your computer security by simplifying the process of finding and uninstalling older versions of Java. The Uninstall tool shows you a list of the Java versions on your computer and then removes those that are out of date.

The tool is available by loading the Java Uninstall tool web page.

You can use the tool by following the below points:

1. On Windows systems, the page checks your Java version before running the tool. If your system is not using the latest secure version, you will be prompted to update before being allowed to run the uninstaller tool.
2. The page will run a Java application and you may be presented with a security prompt asking if you would like to run the Java Detection applet. If you see this prompt, click the Run button to load the applet on the page.
3. The Java Uninstall tool has started when you see a red button that says I Agree to the Terms and Want to Continue.
4. The tool checks to see if there are any old versions that can be removed. If there are none, you will see a message that there are no old versions of Java on your computer, otherwise you will be presented with a list of versions and if you click Uninstall Selected Versions, the process to remove them begins.
5. When the uninstallation of all selected old Java versions has completed, the Old Versions Successfully Uninstalled message will be displayed.

Method 3: Uninstall it from the Control Panel

1. Click Start
2. Select Control Panel
3. Select Programs
4. Click Programs and Features
5. Select Java by clicking on it, and then click the Uninstall button.

I hope this helps in solving your problem of removing the previous Java versions.

Regards,
Lokesh