Get the following programs.

1: AusLogics BoostSpeed.(Fixes corruptions, computer speed issues, and system stability issues)
2: Ccleaner. (for clearing out junk data)
3: Perfect Disk (Use Smart Placement function for best defragging)
4: Malwarebytes. Stops you from going to malicious websites, stops IP intrustions, and is a very good bit of anti-virus.

All of these programs are crackable, or finding the username and password is easy.

going to www.serials.ws can generate you a list of program/product key codes, and it's virus free. Just tell the search bar what you're looking for.
As far as AusLogics goes, you'll need to download a crack file for it (safe) if you don't intend to pay for it (or any of the above programs).

Basically, defrag with smart placement at least once a week, use AusLogics at least twice a week, use Ccleaner once a week, and run Malwarebytes once a week. Your system will thank you, and will stay up and running (healthy) for a good long time.