I’ve been a fan of the simple and effective Windows 7 USB/DVD Download Tool for quite awhile, and have often used it to create a bootable USB flash drive for installing Windows 7.
But I recently ran into a problem with a flash drive after connecting it to my Xbox 360 and using it to move my profile. The Xbox 360 must have made some change to the MBR on the flash drive that the WUDT didn’t like, because it was unable to format the drive.
The WUDT would begin to format the drive, then report:
We were unable to copy your files. Please check your USB device and the selected ISO file and try again.
Windows 7 had no problems formatting the drive, but something was obviously missing from the process.
A quick search in Google turned up the solution. The formatting done by Windows 7 or the WUDT wasn’t cleaning the MBR and partition table.
To thoroughly format the drive so that it can be used by the WUDT, open an elevated command prompt and enter the following commands, using the drive number of the USB drive reported in list disk for the value of select disk #.
diskpart list disk select disk # clean create partition primary select partition 1 active format quick fs=fat32 assign exit
For the curious, here’s a more detailed explanation of the clean command:
Removes any and all partition or volume formatting from the disk with focus. On master boot record (MBR) disks, only the MBR partitioning information and hidden sector information are overwritten. On GUID partition table (GPT) disks, the GPT partitioning information, including the Protective MBR, is overwritten; there is no hidden sector information.
http://technet.microsoft.com/en-us/library/cc766465(v=ws.10).aspx
I would expect that the MBR and partition table would need to be cleaned after formatting a drive for booting Mac OS X, too.
Credit: http://4sysops.com/archives/windows-7-usbdvd-download-tool-wudt-is-unable-to-copy-files/