How to back up HD to XP PC from DVR

Hi,

I have a DVR which I think runs on Linux.

It works fine to local LAN and to Remote Browser and my mobile iPhone and iPad.

Trouble is, I want to back up the 1TB Hard Drive and there is nothing in the manual about this.

There is a USB port for a flash drive usb but I have 1TB so not big enough by far.

The DVR connected to a switch hub which is connected to a Router and ADSL out to web. It is ported correctly as all remote works fine.

My PC is also connected to the same switch but I cannot see the DVR in my Explorer Network and I guess because it is Linux not PC. I see other Win on the LAN.

How can I get around this please?

Thanks

oz