Look for a Lock
Some older Memory Sticks have a switch at the end opposite the connecting leads. This switch, when moved to the unlocked position, permits the transfer of data to and from the Memory Stick. This is primarily present on early versions.
On a PC
First, connect the Memory Stick to the computer. This can be done by using a memory card reader or by connecting the digital camera (if the Memory Stick is used in a digital camera) to the computer with the memory stick inserted. Write protection can be toggled in the Memory Stick's properties. Go to the Start Menu and select "My Computer." Find the Memory Stick (it will be listed as one of the drives connected to the computer) and right-click it. In the drop down menu, select Properties. In the Properties menu, make sure that the box next to "Locked" is unchecked. It should be completely blank and not highlighted. Click "Apply" and then select "OK."
On a Mac
First, connect the Memory Stick to the computer. This can be done by using a memory card reader or by connecting the digital camera (if the Memory Stick is used in a digital camera) to the computer with the Memory Stick inserted. When the Memory Stick appears on the desktop, select it by single-clicking it. Then, go to the File menu and select "Get Info."
A window with the Memory Stick's properties will appear. Under "Ownership and Permissions," make sure that all of the available options display "Read and Write." Once they do, click the "Apply to Selected Items" button at the bottom of that window. This will change the settings for the Memory Stick.