those programmes will be for an antivirus.
I would uninstall all anti virus softwares and stick with windows defender, for 90% of users, this is more than enough protection.
youtube videos stuttering could be a matter of hardware acceleration not being on or off in the browser settings, check and swap to whatever it isnb't and see if it help[s.
regarding performance, could you download the below link (free version) and run a benchmark that covers both cpu and gpu so we can check for any obvious hardware issues. post the 'share my score' or similar link here.