We Were Unable To Copy Your files – Windows USB/DVD Download Tool Posted on by Webmaster IT Support Forum › Forums › Windows › Windows Server 2012 › Installation › We Were Unable To Copy Your files – Windows USB/DVD Download Tool Tagged: Bootable USB, Windows USB/DVD Download Tool This topic contains 0 replies, has 1 voice, and was last updated by Webmaster 12 months ago. Author Posts June 22, 2017 at 10:58 am #2140 WebmasterKeymaster When creating a bootable USB device using the Windows USB/DVD Download Tool, you get this error: We were unable to copy your files. Please check your USB device and the selected ISO file and try again. This is most likely because the WIM file in the source you have provided is larger than 4GB (maximum size supported by the FAT32 file system on the USB drive. Author Posts You must be logged in to reply to this topic.