Ngo1951, U-Viloen upase ibanga lematriki e""Standerton High School"". Ngo-1956, uye waba lilungu lombutho womkhosi waseMzantsi Afrika owawucetywa ngo1956. Uthe esakufumana isidanga sakhe kuphando kwezoMkhosi wamaJoni esifumana kwiYunivesithi yasePretoria, wakhwetyelwa kwisikhundla esiphakamileyo sokongamela indlela emakusetyenzwe ngayo ngumkhosi wamaJoni eMzantsi Afrika ngo 1976. Akubanga kudala ngo uViljoen wonyuselwa waba yingqonyela kumkhosi wamaJoni aseMzantsi afrika. Ngo1977 waphinda wonyuselwa waba yi-""Principal Chief of Staff"" de kwango1980 apho waziphosa kumfo uMagnus Malan iintambo nje-SADF chief