I have a windows 7 computer by the company iBUYPOWER and its fan sound like this. I recorded this with audacity and amplified it so it wouldn't sound so quiet.
計算機Fan.flac
聲道：2
類型：flac
mechanical、Computer、audacity、recording、upload、metal、powered、plugged-in、stereo、amplify、org、background、running、free、track、field-recording、noise、ambience、freesound、Fan、sfstorm、vibration、amplified、soundscape、Electronics、ambient、Machine、system、flac
機械、電腦、大膽、記錄、上載、金屬、動力、插入、立體聲、放大、組織、背景、賽跑、自由、跟踪、現場記錄、噪聲、環境、Freesound上、風扇、sfstorm、振動、放大、音景、電子產品、周圍、機、系統、後手
資料來源：freesound ( https://freesound.org )