Ah man I love the old "run as invoker" trick.
If you really like to have fun, keep a Kali Linux live USB stick on your keychain.
Most computers, even in offices, are not locked with BIOS passwords, or are even set to boot from a USB drive if one is attached.
Most computers also aren't set up to encrypt their Windows drives (and let's face it, almost every desktop you find is gonna be running Windows.)
So you'll be able to get in, mount the Windows drive, harvest whatever you want--or plant anything you want--reboot, and skedaddle.
This is without even getting into hardware you can inconspicuously attach and leave in place.
Of course, all of this information is for research purposes only. We do not endorse criminal activity here!