Which country was formerly named Zaire?

In 1971 the dictator Mobutu Sese Seko changed the name of Republic of Congo to Republic of Zaire. His goal was to replace all the post-colonial names (the capital Leopoldville was changed to Kishasa). However, changing the name of Congo to Zaire was curious, given that the name Congo, which referred both to the river Congo and to the ancient Kongo Empire, was fundamentally "authentic" to pre-colonial African roots, while Zaire is in fact a Portuguese corruption of another African word, Nzere ("river”). In 1997 the name was changed back to Republic of Congo.