Asus TX300CA - Manual (Page 27)

ASUS Transformer Book E-Manual 
Docking
NOTE: When docking the touch panel display while the system is
turned on, Windows® 8 automatically detects the available storage
drives in the dock and launches their respective storage drive
windows via Autoplay. To disable this feature:
1. Go to the Windows® 8 Control Panel.
2. Select Small icons under View by then select Autoplay from the
list of icons.
2. Under Removable drives, select Take no action from the
Removable drive option list.
3. Tap Save to save the new settings then exit.