USB support in the BIOS’s boot menu (although there are ways to get around this; actual use of a CD or DVD can allow the user to choose if the medium can later be written to.
jˌuːˌɛsbˈiː səpˈoːɹt ɪnðə bˈaɪoʊz bˈuːt mˈɛnjuː ɔːlðˈoʊ ðɛɹˌɑːɹ wˈeɪz tə ɡɛt ɚɹˈaʊnd ðˈɪs; ˈæktʃuːəl jˈuːs əvə sˌiːdˈiː ɔːɹ dˌiːvˌiːdˈiː kæn ɐlˈaʊ ðə jˈuːzɚ tə tʃˈuːz ɪf ðə mˈiːdiəm kæn lˈeɪɾɚ biː ɹˈɪʔn̩ tuː.