"The Dursley's house had four bedrooms: one for visitors (usually Uncle Vernon's sister, Marge), one where Dudley slept and one where Dudley kept all the toys and things which wouldn't fit into his first bedroom."
—Description of Privet Drive's four bedrooms.[src]

Dudley Dursley's first bedroom was a room on the second storey of 4 Privet Drive, where Dudley used to reside, until he and his parents were forced to move house in 1997. It is likely that Dudley kept at least one of his televisions or computers in his bedroom.