How to remove write protection on a disk in MS DOS?

Question

DOS

I’m trying to create a text file in MS DOS using the Copy con 123.txt command ,
but I get the following error
Write protect error writing drive a:
I googled and found out that I need to remove protection, but I didn’t find how to do it.

Answer 1

Open a physical lock on a floppy disk:

Answer 2

Some BIOSes also have a ReadOnly setting for the drive.