HTC One M8 User Manual page 219

USB When you plug in an external USB storage device (such as a
storage USB flash drive or an SD card reader), you can view photos
and videos stored on the device right from Gallery and play
songs stored on the device in Music. You can also open PDFs
and edit Office documents.
You need a special cable to connect HTC One and a USB
storage device. HTC One supports USB storage devices
(except portable hard drives) up to 64 GB.
§ Moving apps to the storage card doesn't back up the apps. If you
do a factory reset, your phone loses the apps. You'll need to
reinstall them.
§ When you remove the storage card and insert it in another phone,
the apps on the storage card won't be installed automatically to
the other phone. You'll need to reinstall them.
Copying files to or from HTC One
You can copy your music, photos, and other files to HTC One.
Save and close your files before copying them from your
computer to HTC One, or vice versa.
1. Connect HTC One to the computer using the supplied USB cable.
You'll see options for viewing or importing files on the computer
screen.
Storage and files 219