Microsoft Security Essentials is fine as an anti-virus scanner with some anti-spyware built in, but no anti-virus will find all malware threats.
That is why we usually recommend the free versions of Malwarebytes Anti-malware and SUPERAntiSpyware.
HiJackThis is not an anti-malware scanner. It is a tool to find out running processes on a system.
Mark
I am already using security essentials. Is it necessary to run an antispyware antimalware along with it? If so which one? Usually the top rated are malwarebytes and hijackthis...

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