Desktop Lockdown with Windows Disk Protection ( Steady State ) ?

[kblumen]

I have been heavily researching different ways to lockdown my 400+ Windows XP SP3 Desktops (in two countries.)
I am wondering if SteadyState is really the way to go.

I have a java-based VoIP application that needs to be updated from time to time. It lives in a centralized area on each desktop (C:\Java\Cache & C:\Windows\Sun\Java\Deployment). Is there a way to keep these areas persistent? Alternatively, I understand that I might be able to upgrade each desktop with a custom script however this Java Application might not cooperate.

I have toyed with the idea of using a virtual desktop environment (that would live on each desktop). Any ideas or suggestions would be greatly appreciated. Thanks so much for your time in advance!

GPAnswers is terrific! - Thanks for all the tips!

[kblumen]

UPDATE :: It was just too easy. I was really over-thinking it :-)

ANSWER: Ok my java application is simply a bunch of files that I can copy to each workstation during the allotted critical update process (files will come from a workstation that I manually update)