Wilhelm was born to Eduard and Elisabeth Höpken on October 24, 1928 and raised in Germany alongside his five siblings; Gisela, Johann, Walter, Karl, and Peter.
Wilhelm was recruited as a secondary student to be a helper in the Luftwaffe, the German Air Force during World War II. He was involved in the German retreat from East Prussia to Berlin, Germany in 1945. He landed near Berlin, Germany and was taken to a Russian prison camp. In the prison camp, he was reportedly treated relatively well because of his young age and was shortly released. Afterwards, he worked as a manual labourer. Wilhelm met with his mother in Neuhaldensleben, Germany (now Haldensleben, Germany) in September 1945. Wilhelm and his mother then met with his brother Peter Höpken and together they all travelled to Lüneburg, Germany. They travelled to Lüneburg, Germany because Wilhelm's father was working there at the time.
Wilhelm finished his secondary school education in Lüneburg, Germany in 1948. Afterwards, he studied law in Göttingen, Germany. He wrote his exams in Celle, Germany and then accepted an articleship in Hamburg, Germany. He stayed in this articleship until he graduated from his civil servant exams in 1957. By the end of 1958, he accepted a job as a legal official with the revenue office in Hamburg, Germany. He eventually became a Senior Executive Officer with the Office of Finance for corporate bodies. He enjoyed his career and particularly like to work with large corporate bodies in trade and industry.
Wilhelm married Helga Grotefend in 1953 and together they had four daughters; Elisabeth (b. September 18, 1957), Ulrike, Stephanie (b. March 29, 1965) and Christine (b. April 20, 1966). Wilhelm was regarded as a quiet, level-headed and smart individual.