Duba wurin da ke ƙasa sannan ka amsa tambayar daga baya a cikin harshe ɗaya kamar yadda wurin yake:  Passage: An haifi Gates ne a Seattle, Washington, a ranar 28 ga Oktoba, 1955. Shi ne dan William H. Gates Sr. (b. 1925) da Mary Maxwell Gates (1929<unk>1994). Kakanninsa sun haɗa da Ingilishi, Jamusanci, Irish, da Scots-Irish. Mahaifinsa sanannen lauya ne, kuma mahaifiyarsa ta yi aiki a kwamitin gudanarwa na First Interstate BancSystem da United Way. Mahaifin mahaifiyar Gates shi ne J. W. Maxwell, shugaban bankin kasa. Gates yana da 'yar'uwa babba, Kristi (Kristianne), da ƙaramar' yar'uwa, Libby. Shi ne na huɗu na sunansa a cikin danginsa, amma an san shi da William Gates III ko "Trey" saboda mahaifinsa yana da ƙarshen "II". Iyalin sun zauna a yankin Sand Point na Seattle a cikin wani gida wanda wata mahaukaciyar guguwa ta taɓa lalata lokacin da Gates ke ɗan shekara bakwai. Tun da farko a rayuwarsa, Gates ya lura cewa iyayensa suna son shi ya bi aikin lauya. Sa'ad da Gates yake matashi, iyalinsa suna zuwa coci a kai a kai na Cocin Kirista na Ikilisiya, addinin Furotesta da aka Gyara. Iyalin sun karfafa gasa; wani baƙo ya ba da rahoton cewa "ba shi da mahimmanci ko zukata ne ko pickleball ko yin iyo zuwa tashar jirgin ruwa... koyaushe akwai lada don cin nasara kuma koyaushe akwai hukunci don rashin nasara".A 13, ya shiga Makarantar Lakeside, makarantar shiri mai zaman kanta kuma ya rubuta shirin software na farko. Lokacin da Gates ke aji na takwas, Kungiyar Iyaye mata a makarantar ta yi amfani da kudaden da aka samu daga sayar da kayan makaranta na Lakeside don sayen Teletype Model 33 ASR da kuma wani lokaci na kwamfuta a kan kwamfutar General Electric (GE) don daliban makarantar. Gates ya nuna sha'awar tsara tsarin GE a cikin BASIC, kuma an ba shi izini daga azuzuwan lissafi don bin sha'awarsa. Ya rubuta shirin kwamfutarsa na farko a kan wannan na'urar: aiwatar da tic-tac-toe wanda ya baiwa masu amfani damar yin wasa da kwamfuta. Gates yana sha'awar injin da kuma yadda koyaushe zai aiwatar da lambar software daidai. Sa'ad da ya yi tunani a kan wannan lokacin, ya ce, "Akwai wani abu mai kyau game da na'urar". Bayan Ƙungiyar Uwa...  Tambaya: 'Yan'uwa mata nawa ne Gates ke da su?
wata 'yar'uwa babba mai suna Kristi (Kristianne), da ƙanwata mai suna Libby