FULL PRODUCT VERSION :
java version "1.6.0_01"
Java(TM) SE Runtime Environment (build 1.6.0_01-b06)
Java HotSpot(TM) Client VM (build 1.6.0_01-b06, mixed mode, sharing)

ADDITIONAL OS VERSION INFORMATION :
Windows 2K, 2000, XP, Vista

EXTRA RELEVANT SYSTEM CONFIGURATION :
See closed Bug ID 6357269 for the same problem

A DESCRIPTION OF THE PROBLEM :
On any Windows Machines the return of "VirtualMachine.list()" is empty. In result of this JConsole and JPS doesn't work.

I recognized this Bug on approximately 4 of 25 Windows machines. This Bug occures on several user accounts, independent of the fact, if this was an administrator or a restricted user. It is possible, that this Bug occures on one account and on another account on the same machine it doesn´t occure.

At some machines it helps, if you create a new user account. On other machines this doesn´t work. (A new user on Windows is a copy of the hidden folder "Default User")

Trying to reinstall java underneath several conditions doesn´t cleared the Bug.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
I think it's not easy to reproduce this Bug (see Description)

The following steps describes a successfull attempt to reproduce the Bug:

1. Install a new, clean Windows Vista Buissnes with one User
2. Install some basic Drivers and Vista Updates
3. Install JDK 6 Upd 2

Try JPS, JConsole or VirtualMachine.list() to see the Bug.


REPRODUCIBILITY :
This bug can be reproduced often.