Can I connect my wireless DVD player to a network hard drive containing movies thru the network or do I have to use the USB connection on the DVD player?
What's the make and model of the DVD player? And what kind of "network hard drive" is it? Does it support DLNA?
depends on models
1) Run an Ethernet cable to the DVD player.
2) Buy an Ethernet to Wireless Bridge adapter.
How To Connect Your Blu-ray Player To A Wireless Network Using The Optional Samsung Wireless Adapter
perhaps this guide can help you