"Ideas for solving problems"
Although the flash drive now has a read-only file, can realize the flash drive read-only function, but this is too easy to break. Because readers require that you implement read-only on any computer, in addition to the physical limitations of the method, we can only use the software to implement the write limit. As you know, for NTFS partitions, we can implement read-only effects through the settings of permissions, so we do this by using permissions.
"How To solve problems"
First insert the flash drive, open Explorer, select the Flash drive, right-click Select "Format", and select "NTFS" in the pop-up window file system to format the flash drive in NTFS format (Figure 1).
Figure 1 Format the flash drive
Format will delete all the data on the flash drive, before the operation, please do a data backup, do not want to format friends can also use the command line "Convert u:/fs:ntfs/x", for lossless conversion. Of course, there are data risks as well.
Then press the prompts to copy the required files to the flash drive, and continue right click on the flash drive select properties → security → edit, the Write permission for everyone in the open window is set to deny so that no user can write the file to the flash drive (Figure 2).
Figure 2 Flash drive permission settings
Because the permission settings are stored on the flash drive NTFS volume, so even if this flash drive is plugged into another computer (or other Windows), the write denied permission is still valid, and when the user attempts to write the file to the flash drive, the system pops up "you need permission to do this" to reject the write prompt (Figure 3).
Figure 3 Deny Write
Of course, if you really need to write the file to the flash drive, just re-enter the permissions attribute edit, and then add your account to the Allow list, and set it to full control. It is important to note that to ensure a read-only validity, you must remove the Write account permissions after the file write is complete. If a read-only flash drive requires permission changes on another computer, you need to go to advanced settings and change the flash drive ownership to the current computer's administrator account in order to make changes (Figure 4).