When the war began, Windisch was serving in the 177th Infantry Regiment. Wounded in action on 21 November 1914, he joined the German Air Force on 22 January 1915. After training at the Military Pilot's School in Leipzig-Lindenthal, he was promoted and assigned to FEA 6 as an instructor. On 1 May 1916, he joined FFA 62, flying two-seaters on the Russian front and downing an observation balloon for his first victory on 25 August. Carrying out a special mission on 2 October, Windisch landed his plane behind Russian lines and left his observer behind to destroy a strategic railway bridge near Rowno-Brody. Returning the following day, Windisch picked up his observer, Oberleutnant von Cossel, and flew back across the lines. For having successfully destroyed the bridge, the two men were personally decorated by the Emperor on 18 October 1916. On that day, Windisch became the first and only pilot during the war to receive the Prussian Order of the Crown, 4th Class with Swords. The following month, he joined KG II as a reconnaissance pilot on the Western Front. With the formation of new Jastas, experienced pilots were needed and Windisch was posted to Jasta 32 on 20 February 1917. After further training, he returned to the front as a fighting pilot, scoring 7 more victories by 4 January 1918. On 10 January, he was posted to Jasta 50 for two weeks before assuming command of Jasta 66 on 24 January 1918. Before he was shot down on 27 May 1918, Windisch scored 14 more victories. Thought to be a prisoner of war in the hands of the French, his Blue Max was approved on 6 June 1918 but Windisch was never seen again and his death remains shrouded in mystery.