How to create bootable USB without administrator rights?
Unfortunately not. Non-administrators can not change the MBR.
Maybe if you have the Virtual box at work. And have access to USB.
It is also possible to write a bootable CD. Use the application Brasero.
You could ask your IT department at work to make a bootable USB for you.
If you can boot the Ubuntu Live CD, (or Live USB), you should be able to run Startup Disk Creator.