Check for Microsoft Java Virtual Machine

The window below runs a small Java applet to display version information about the Java virtual machine installed on your system:

"You do not appear to have a Java Virtual machine installed"

If the window above displays information in the form:-
BuildIncrement: 3810 MajorVersion: 5 Description: Microsoft (R) VM for Java, 5.0 BuildNumber: 0 Minor Version 0

You have a Microsoft JVM correctly installed. Build Increment 3810 is the current version which contains security patches to build 3805.

If the window displays "Non MicroSoft JVM" you have a virtual machine from someone other than Microsoft - typically Sun.

If there is no window displayed and you see the text "You do not appear to have a Java Virtual machine installed" . You do not have a Java virtual machine installed on this machine or alternatively it is not enabled in this browser.

Further information about Microsoft Java virtual machine installations is contained in the registry. Run "regedit" from the Windows start button. If a Microsoft Java virtual machine is present there will be a registry key

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Java VM

If this family of registry keys is present then you have a Microsoft JVM installed. If it is absent you do not.

The value of the key "Classpath" will often contain a value which has version number information implied in it. For example on a system with build 3810 installed the value will be ";C:\WINDOWS\Java\Classes\jgl310.jar;C:\WINDOWS\Java\Classes\cryptix32.jar"

Similarly, a system with a Microsoft JVM installed should have *.jar files in the java\classes folder under the windows installation. Typically: "C:\windows\java\classes". On a system without a Microsoft JVM installed the folder will not contain the *.jar files.