Hi.. no admin rights needed - just plug in your USB stick (or your USB drive in your case) and double-click the icon of the program of your choice. I have mine all organized in folders by type of program (ie: paint/multimedia/games/utilities, etc) and then just choose the program and run it.

If you already own photoshop CS2, then you can check out the link from here... please be sure that you do own the full retail versions of any portable you find on the internet...

Design Talk: Portable Photoshop CS2 (26MB)

There is some work involved.. but it works fine! Good luck with this..!