after many hours over Christmas trying to upgrade a Xbox one and a Xbox one s to 1TB HDD i finally sorted it both have now new 1TB HDD and working perfect i was having a issue with the script or (thought it was) for some reason it would not work for me i followed all the instructions on setting up the new drive and so on but it simply would not work when it came to the OSU1 update it simply returned a error code immediately and would not go any further on both Xboxes i did try everything and was getting very frustrated to say the least so i went back to basics on close inspection of the SATA to USB adapter cable and the USB port on my laptop i realized i was plugging in a USB 2 adapter cable into a USB 3 port on my laptop i must have not realized i bought a USB 2 adapter for some reason i cannot explain it never crossed my mind and just kept plugging it in to the same port thinking the error was the Xbox script when formatting and setting up the HDD everything seemed ok no errors on the HDD or laptop but when it was put in the Xbox obviously there was a error that stopped the OSU1 to start the update on my first attempt when i plugged the HDD adapter into the correct port i hastily formatted the new drive to NTFS file system i was so excited removed it and installed it in the Xbox in my haste forgot to setup the HDD using the script but it was to late it was in the covers back on so just thought i would try a OSU1 update plugged in the OSU1 into the Xbox turned on and it started straight away was expecting a error but went thru the update without any issues on the other Xbox one s i just formatted to NTFS installed it and the same results both worked perfect it worked for me without using the script hope this helps other people don't forget to check what USB port your plugging into