I set up a Linux (Gentoo) computer for a previous XP user, and here is the screenshot! Thought you all might enjoy!
How I did it,
KBFX 0.9 with the light theme (http://www.kde-look.org/content/show.php?content=38934) You could also use the "KBFX - XP like" theme.
Use one of the provided menu buttons and drag it onto the KBFX applet.
Right click on Kicker and choose "Configure Panel", goto appearance and put the path to XPbar into the background field. Make sure you have kicker set to small size.
Use the plastik windeco, and the Karamik widget style, and the RedmondXP color scheme. I also used the Redmond splash screen.
Make TBird & FF look cool with your favorite theme. Mine is noia 2.0 extreme.
Find a good wallpaper an you're all set!
I got the "start" button from another theme on here but I don't know which one anymore, but it was GPL so I'll include it here.
I painted my own XPbar and it is included in the files. If it does not fit right you may have to modify it.
Good Luck fooling your boss!