Setting your important or personal files to read-only can help protect them from unintentional or unauthorized changes. When a file is set to read-only, it cannot be changed.
Right-click the file or folder you want to set to read-only, and then click Properties.
Click the General tab, select the Read-only check box, and then click OK.
If you need to make changes to the file or folder later, you can turn off the read-only setting by clearing the Read-only check box.
Setting a folder to read-only makes all the files in the folder read-only. It does not affect the folder itself.
Read-only files cannot be changed, but they can be copied, moved, renamed, or deleted.
It is possible that changing a read-only file can cause a program that relies on the file to stop working properly, so be sure that it's okay to change a read-only file before you proceed.