When you need to connect your BlackBerry Z10 to your PC, you may need to activate USB Mass Storage - so-called the Mass Storage Mode on the phone. This mode lets you easily and quickly transfer files back and forth from your SD card to the computer.
Normally, on the first time when you connect Z10 to a Mac or PC, you may have some trouble finding the mounted drive. In that case, you will need to verify whether the USB Mass Storage mode is activated or not; otherwise, you'll be stuck wondering why nothing happens.
Here’s how to switch it on:
1. Head back to BlackBerry Z10’s Home screen.
2. Here, swipe down from the top of the screen.
3. Then tap on Settings.
4. Tap Storage and Access.
5. Scroll down to the bottom and switch the USB Storage Mode ON.
6. From then on, everytime you connect your BlackBerry 10 device to your PC, you'll see your SD card listed as a mounted drive.