Today, I decided to doublecheck if there are any viruses running in the background by looking at the exe. files using task manager. There were a few .exe files that I slightly doubted (e.g., the csrss.exe and the atieclxx.exe apps that didn't have any description and the Properties window doesn't appear after I right click and click Properties).
I searched up a bit more about those two apps. The csrss.exe is a 'user-mode portion of the Win32 subsystem' and the atieclxx.exe is a program of ATi Graphic card drivers. But these files may get corrupted or a virus/spyware may imitate its name. It turns out that when there are actually virus imitations of these two apps, usually you would see two apps of the same name running (e.g., two csrss.exe running at the same time or two atieclxx.exe. running at the same time.
So I decided not to worry about those two, and since norton didn't notice anything, it's probably safe. But later I noticed there were two wisptis.exe running at the same time. One didn't have any description and nothing pops up when I right click and then click properties.
The other one had a description that said 'Microsoft Pen and Touch component' and the properties panel does function properly for this one. I'm worried about whether the former is a virus imposter. Though it probably is just my suspicions, I wanted to confirm it with Norton.
Thank you! 
P.S., I'm not 100% sure that this post belongs in this forum, so I'm sorry if I got it wrong. >->