You are still on Windows XP & you use Microsoft Security Essentials.
Windows 7 or 10 isn't too expensive so you should probably eventually save up for that. Also I would recommend that you stop using Microsoft Security Essentials & use something like Emsisoft Anti-Malware or Internet Security once you upgrade your OS - Security Essentials is pretty terrible.
I would also recommend that you use Zemana Anti-Malware as Real Time for now as well as Demand & HitmanPro as a demand scanner.