how to lock down a desktop?



I have couple desktop which needs to only launch one application and nothing
else. So, when use remote desktop to it, they just login and start the appl
(either desktop or start menu).

how to lock down a windows xp pro or windows 7, so, there is only one app?

i know it might be a lengthly steps or process, i welcome url to site with
step by step instructions.

thanks.


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