Microsoft's withdrawal of its virtual machine (VM) for Java has many administrators confused about the state of support for the VM through service packs, and asking what service packs for Windows 2000 will do (if anything) to the Microsoft VM. Some setups rely on the presence of the Microsoft VM to work correctly and administrators are worried that upgrading to a future Windows 2000 service pack will break Java compatibility. So what's the real story?
While adding service packs to Windows will upgrade the Java virtual machine, it does not de-install it. If the VM is present, Windows Update will upgrade it, but it cannot be installed anew from Windows update.
While Microsoft no longer distributes the VM, it may still be possible to obtain the VM from an independent software vendor with a license to redistribute the product. However, in the long run, it may be best simply to obtain and migrate to a non-Microsoft Java VM, such as Sun's 1.4 implementation of the VM (which is by all accounts very stable and speedy).
To determine if the virtual machine is installed, type jview at a command line. If the virtual machine is not present the command will return an error. A newly installed copy of Windows 2000 with the gold release of the operating system (i.e., not patched with any service pack) will almost certainly have a copy of the VM, but a slipstreamed copy of Windows 2000 (i.e., a manufacturer-issued copy with SP4 preinstalled) will not. The VM files are not covered by Windows File Protection and will not be replaced if edited or tampered with manually.
Serdar Yegulalp is the editor of the Windows 2000 Power Users Newsletter. Check out his Windows 2000 blog for his latest advice and musings on the world of Windows network administrators – please share your thoughts as well!
This was first published in October 2003