I've been struggling with this for a few hours. From many different articles on CentOS7 installs from USBs and cygwin help files I found this to work from Windows 10 64 bit. Rufus, Linuxlive Unet all failed me this time.

1. Install Cygwin 64bit
2. Run Cygwin as administrator
3. Type "cat /proc/partitions"
4. figure out which disk is your usb (it will show letter next to partition - mine showed F next to sdb1)
5. Type this in "dd bs=4M if=/cygdrive/c/Users/James/Downloads/ClearOS7.iso of=/dev/sdb" (substitute the file path for your clearosISO; do not put the 1 next to sdb; and BE VERY SURE ITS YOUR USB, as dd will write over whichever harddrive you put there) (Note: Cygwin mounts your windows c: as /cygdrive/c/ and d as /cygdrive/d/ etc)

It would be nice to see some user friendly official USB installation support from ClearOS, everybody hates DVDs. I threw out my stack of blank disks 6 years ago.

Also worth noting the installation UI is very different (much better in my opinion) and the process for creating a software raid installation has changed. This time I only needed to create the 2 swap partitions for RAID 1, then one RAID partition and select two disks. For ClearOS 6 you had to create the partitions and then the RAID disk with the separate partitions (rather than just selecting the disks.