I want an all-one flash drive that will contain Windows 8.1 AIO, WindowsPE for Backupper software, and MS DOS. It must be bootable in UEFI environment. Wanting Windows 8.1 AIO is self-explanatory. Backupper is a program used to make/clone drive images. To restore images - one needs to create a bootable WindowsPE drive using Backupper software. I also want MS DOS so that I can use the drive to flash hardware ROMs/firmwares, etc. My PC is using UEFI environment, so the drive needs to be compatible be able to detect/see UEFI OS/drives, etc., BUT does not necessary have to be UEFI-bootable because I can enable Compatibility Mode in BIOS/UEFI to allow non-UEFI booting. I also want to place huge backup files on it, so exFAT is likely the only possible file format I can use, right?