Restore from a backup, or delete the data files and start over. Close Windows, power off your computer, then turn the power back on. Restart your computer while the power remains on. Click Start, Shut Down, then choose Restart. Since you are going to make new entries, having a data file as read only does not work.
Floppy disks have small openings at the top.
Closing the window on the right side makes the disk read only . Since you are going to make new entries, using a write-protected disk does not work. This is a program provided free with Windows. ScanDisk can be used to repair some drive problems.