Some memory cards have a read only switch, try switching that. If it did not help try access it on the another computer. If the card was removed from a camera, use a usb cable connected to the camera to access files.
Usually there is a switch that locks the cards
Slide the write protect tab to the unlocked position.
The fact that the memory stick is write protected will not prevent you "reading" the contents. Thus there is no problem in making the copy from the stick to the memory card.
how to reboot a flash drive?
You can't. Hopefully you have a tab on the memory card. If you do, just move the tab to allow writing to the card.
take the memory card out of the camera and push the little yellow lock upwards to unlock it.
it can remove..
There should be a small lock button on the side of the memory card. Its probably locked.
you should remove the contents if possible and reformat
Flip the "Write Protect Switch" on the side of the card, - Format the card (avoids file ownership problems).
You would move the little slide that is on the side of it.
You can put a password on a memory card with the correct programming.
A little switch on the card is set to "write protect" mode which prevents the card from being written to or overwriting any existing data on it.