Monthly Archives: June 2016
This article demonstrates how to copy a Windows installation source to a USB flash drive (UFD), and make that UFD bootable, without using any third-party app. Every now and then, such an article must be re-written to update the sum of knowledge. Only the tools included with the operating system are used. This article assumes you have at least Windows 7. Also, it assumes that the OS you’d like to copy to a UFD is Windows Vista, 7, 8, 8.1 or 10 and is already available to you on DVD or in folder somewhere.
BootSect.exe and BootRec.exe are both components of Windows Vista and later. They help make disks bootable. Both are included with a Windows installation DVD, USB flash drive or ISO.
/mbr switches. It can be found in the “boot” folder, at the root of the Windows installation media. Also, a copy it can be found in the same places as BootRec.exe. (Read below.) Starting with Windows 8, a copy of it is installed in “C:\Windows\System32” folder, but this was not the case with Windows 7.
/RebuildBCD switches. However, it is harder to find. It is only exposed if a computer is booted into Windows Setup or Windows Recovery Environment. Otherwise, one has to extract it from the “sources\boot.wim” file of the Windows installation media, or the elusive “winre.wim” file. These .wim files can be mounted via DISM or browsed using 7-Zip. Once either of the two images of “boot.wim” are mounted or opened, BootRec.exe can be located under “Windows\System32” subfolder.
Update (2018-08-09): Updated with additional info.
 The “winre.wim” file is not guaranteed to exist on all Windows installations; OEMs may not include it, may rename or may place it somewhere different. Depending on the Windows version, edition and installation condition, this file may be found on the system volume, boot volume or recovery volume. (On is C:, the other two are hidden volumes.) Within that volume, look for a hidden “Recovery” folder. In that folder, there is a randomly named (GUID) subfolder. Inside that folder, you find “winre.wim”.