I've found MBAM will detect badware that Norton or Super Anti Spyware won't, each security program has a different scan engine and definition data bases. I use Norton on auto scan and run other 1-2 times a month.
I think most non-tech users now use the term "virus" to include all types of badware, worms, Trojans, viruses, rootkits, run time exploits, info stealers, etc.
To reiterate Deacon's advice, I've found many hardware issues too. New and experienced builders often buy very high end components and try to run them with a $40 PSU.