mˈaɪkɹəsˌɑːft ɹɪzˈɜːvz ɐ tʃˈʌŋk ʌv dˈɪsk spˈeɪs jˈuːzɪŋ ðɪs ˌɛmˌɛsˈɑːɹ pɑːɹtˈɪʃən tˈaɪp, tə pɹəvˈaɪd ɐn ɔːltˈɜːnətˌɪv dˈeɪɾə stˈoːɹɪdʒ spˈeɪs fɔːɹ sˈʌtʃ sˈɔftwɛɹ kəmpˈoʊnənts wˌɪtʃ pɹˈiːviəsli mˌeɪhɐv jˈuːzd hˈɪdən sˈɛktɚz ˌɔn ˌɛmbˌiːˈɑːɹ fˈɔːɹmæɾᵻd dˈɪsks.
Microsoft reserves a chunk of disk space using this MSR partition type, to provide an alternative data storage space for such software components which previously may have used hidden sectors on MBR formatted disks.