Adverts randomly playing in the background and computer become really slow...?

[Ti]

First of all Norton is famous for slowing down the the computer
Second of all You should Download Malwarebyte to scan for malware, spyware, adware and /or viruses
Third of all your computer is probably slow because the data on the hard disk is fragmented(I dont care if your computer is empty its still has files, and imagine a part of one file split in over 100 parts, then imagine all the rest of the fragmented files) you should defragment your hard disk