so you'll need the POD connected to your PC using USB, then the guitar goes into the HD500 input, and your output device (headphones or speakers or amp) needs connecting to the POD's outputs.

edit can then be used to edit settings in the POD, but it's the POD that's producing the audio, and not the edit application.

you would also need to check in the system menu on the PODthat the correct input on the POD is selected to be used.  that setting can either be a per preset setting or a global setting.

Hope this helps, but please reply if you're still stuck, and give us more information about how you have everything connected and what you're trying to achieve with using the devices in the way you have them connected.

Cheers

Rowbi