Upper Canada was a historical region that existed from 1791 to 1841 and encompassed the southern portion of present-day Ontario. The designation "Upper Canada" was used to distinguish it from Lower Canada, which referred to the region that would later become the province of Quebec.
Windsor, Ontario, is situated in southwestern Ontario, near the border with the United States. Historically, this region was part of the Western District of Upper Canada, but it was not considered to be part of Upper Canada proper. The Western District was administered separately from the rest of Upper Canada and had its own distinct history and development.
Therefore, while Windsor is geographically located within the province of Ontario, which was once part of Upper Canada, it is not generally considered to be part of Upper Canada itself.