Change permissions to external HD

[Crow]

I need to change permissions to an external HD because sometimes doesn't let other computers write files. I can't do it using PCManFM. How can I do it?

Here is an image. Tried as root and didn't work.

[muungwana]

what file system does the hard drive use?

With certain file systems like fat and ntfs,the file permissions can not be changed as these file systems do not support unix permissions.

With these file systems,permissions are simulated and are set at the time when the file system is mounted and they stay put,cant be changed afterwards,the only way to change them is to remount the file system with new permissions.

[Crow]

Is FAT32

The HD has problems when used in other computers like Mac and some Windows machines, never in Linux

[muungwana]

The permissions will have to be set when the drive is being mounted.

The point to do that will be to add the drive to "/etc/fstab" with mount options you prefer and hope the tool you use to do mounting will respect them.

[Crow]

Thank you muungwana, had to sleep was 1:30 in the morning  7:00 o'clock now.

The HD had a virus and didn't mount appropriately so I thought in a corrupted partition table, I  rewrote the partition table and formatted again, now it mounts and I can write to it but when I tried to write an antivirus from Windows it reported "disk full" and it was empty    I copied a folder and now windows reports a disk the size of the new folder. I don't have a Mac to test for now. Permissions in Linux are as in the first image.

This disc is used to carry files between computers so the need to be read from multiple machines.