Question about Teamviewer which is installed but not running in the background

Hi all,

I purchased an Asus laptop a year and a half ago. After removing a program yesterday using windows programs and features I only just noticed that Teamviewer was installed. 

It seems it was pre-installed on the laptop along with the usual Asus related bloatware programs that Asus are well known for. My own fault for not even checking.

It was Teamviewer version 11 - Free licence (non-commercial use only).

Now although this was fully installed, it was never running in the background. I know it had never run in the background because when I launched it for the first time over the weekend, a licence window popped up asking me to accept before the program started. Also "Start teamviewer with windows" was unchecked in the options.

My question is this, could it be possible for someone to have unauthorized access to my laptop with TV in this state (installed - but not running in the background) without me knowing?

For example if I left my laptop on overnight, someone could have logged in, taken personal files then logged out unbeknownst to me.

Sorry if ithis seems like an amateurish question but I'm not very tech savvy and Teamviewer is new to me so I'm currently learning about it,  any answers would be greatly appreciated.

Thankyou