He was son of Henry Villiers Stuart (1803-1874) Lord Stuart de Decies. Henry Windsor had an unusual variety of careers, in the army, the church and politics. He was a cadet in Prince Liechtenstein's Regiment (the Regiment of Light House) of the Austrian Imperial Army 1844-1846.He was an ensign in the 20th British regiment 1846-1847. He was appointed Vicar of Bulkington, Warwickshire in 1852 and Napton in 1855. He resigned Holy Orders in 1871 in order to stand for Parliament as M. P. for Co. Waterford 1873-1874 and 1880-1885.

In 1865 Henry Windsor married Mary, second daughter of Ven. Ambrose Power Archdeacon of Lismore and son of Sir John Power 1st Bt. Of Kilfane, Co. Kilkenny.

In 1874/75 Henry Windsor vacated his seat in Parliament in order to pursue his claim to his father's title 'Lord Stuart de Decies.'He was unsuccessful in this claim, as the validity of his parent's marriage could not be proved.After the battle of Tek'el'Kebir in 1882 Henry Windsor was commissioned by the government to visit Egypt and to report on the condition of the people. He was the author of a number of books including - Nile Gleanings 1879, Egypt after the War 1883, Funeral Tent of an Egyptian Queen 1882, Adventures amongst the Equatorial Forests and Rivers of South America 1891. A copy of this work is in the Waterford County Museum Collection.

In 1882 he introduced the Labourer's Cottages and Allotments (Ireland) Bill which was passed on 18 August 1882. He tried to establish an agricultural College in Ring.This was unsuccessful but the shell of the building developed into Colaiste na Rinne. He was a member of the Waterford Historical and Archaeological Society. He drowned on 12 October 1895 aged 65 after falling from his boat on the river Blackwater.