Unfortunately - no. You can only have one of the operating systems on that flash drive (which should be set as bootable). Here's how to create installation media for Windows 8.1: http://windows.microsoft.com/en-us/windows-8/create-reset-refresh-media the process is basically the same for Win 10.
Unfortunately - no. You can only have one of the operating systems on that flash drive (which should be set as bootable). Here's how to create installation media for Windows 8.1: http://windows.microsoft.com/en-us/windows-8/create-reset-refresh-media the process is basically the same for Win 10.