If it is a work computer, "system admin" will be whoever looks after the computers in your company. If it is your own private laptop, "system admin" unfortunately is you!
Its basically the person that would be maintaining your computer in a company environment. If you don't have one, bring the laptop to a computer shop to fix it.
It means system administrator. If this is your work computer, contact your helpdesk. If it is your private computer, call tech support and get admin rights on your system.