Can't share usb hard drive with Windows or mac

Is the drive plugged into an Airport Extreme or Time Capsule??

Mainly we deal with airport issues here.. If it is plugged into a computer you will need to deal with it.. perhaps via the OS you are using.

Tell me more if it is plugged into the AE or TC.. what is the disk formatted and partitioned. To work correctly it should be GUID partitioned and HFS+ format. AE cannot recognise NTFS.

LP asked how the drive was formatted.

Needs to be Mac OS Extended (Journaled), also known as HFS+.....as LP mentioned above.

ExFAT and NTFS will not work with the USB port on the AirPort routers. More info here:

AirPort base stations: About USB disks - Apple Support

PCs and Macs accessing a drive that connected to a Airport Extreme never see the file system on the drive. The AE handles that. The drive MUST be formatted as Mac OS X Extended Journaled. If you are expecting to be able to unplug it from the AE and physically plug it into a PC via USB, that's not going to happen.

If you plug a Mac OS formatted drive directly into the USB port of a Widows machine, no.

If it's being shared over the network via an Airport Extreme, or even directly from a Mac, yes, because the client machine (Windows) NEVER touches the file system on the drive. That's not how network file sharing works.

so what format works for pc and mac?

Did you read the support document that I linked? It tells you this information.

Mac OS Extended (Journaled) will work with both Mac and PC if the drive is connected to the USB port on an AirPort Extreme or AirPort Time Capsule.