The Microsoft search engine launched in 1998 that preceded Bing was MSN Search. Microsoft introduced MSN Search in the third quarter of 1998, initially using results supplied by the search company Inktomi rather than a fully independent Microsoft index.
MSN Search evolved through several names and technical changes as Microsoft expanded its online services. In 2005, Microsoft began developing its own search technology, and the service later became Windows Live Search. In 2008, Microsoft shortened that branding to Live Search.
Bing arrived in 2009 as the successor to Live Search and was marketed as a “decision engine.” That history can create a common quiz trap: Live Search was Bing’s immediate branded predecessor, but it was not the search engine launched in 1998. The date in this question identifies the earlier service as MSN Search. Kumo was a proposed internal codename associated with Microsoft’s later search work, not the 1998 public product.