Thank you. I succesfully used Win32 Disk Imager but I had to remame ImgBurn's ISO file with a ".img" extension.
Incidentally, it was less than staightforward to reformat the resulting flash drive under Windows 7. This was only a test and I didn't intend to make a permanent copy of Linux on the flash drive.
I successfully used ImgBurn to copy a bootable Linux Mint DVD. Then I unsuccessfully tried to convert the resulting ISO file into a bootable USB flash drive by using Microsoft's Windows 7 USB/DVD Download Tool. The Microsoft program says "Invalid ISO File." Who to blame? What should I do?
I bet many people want to create bootable USB flash drives from bootable DVDs. Shouldn't an explanation of why this feature is not included be in the FAQs?