AntiVirus and AntiMalware
Face it, if you use Windows, you must have at least a decent and up to date antivirus/antimalware software installed to keep your computer safe. These free solutions are a good start. Microsoft does include basic anti-virus, but it can be buggy and sometimes miss some rather large threats to your system's security.
Some of this software will only run a constant live scan or requires you to manually scan your computer from time to time in order to keep you safe.
Use the link below to get your Anti-Virus Software: