Joanna:
I tried another stick (a 16GB); and now the Install Program (full graphics and troubleshooting text modes) tells me that the install cannot continue since there is no root (/) partition.
IIRC, All we need was something larger than 10GB.
Was there something I needed to do, other than blanking the drive via formatting for the install?
I understand that you’ve installed on USB3 Sticks. Any luck on the USB2 Gen Drives?
Thank you 
there is no root (/) partition
During partitioning, you should define mappings between partitions and mount points.
In your case, you should configure the partition to be used as /
I formatted the pen drive via Windoze. That is the error message the Qubes installer has indicated.
So, I’ll need to boot up Linux; and partition the USB Flash Drive as a “/” root partition deliberately, or
should I format the pen drive on linux, then proceed? (6 and a half-dozen or another - ^_^)
Thanks.
Installer gives you option to partition it there. There are some predefined
layouts ("LVM" by default), but there is also option to select partitions
manually. I suggest that you choose it, remove all the partitions from this
stick (this done by windows) and select automatic layout proposed by installer.