my advice is, get rid of firewalls, antiviruses and similar stuff, it works for me, those things slow down ur computer, u just need to be careful with ur steps on internet, not clicking suspicious urls, or installing weird stuffs, and stay away from pr0n sites. ha!
no, seriously. just get rid of anti-whatever softwares, unless of course that u have information of national security (or sensitivity information from ur job). back up things like photos and documents, everything else can be downloaded again.
and once in a while run an online scan.