Transferring video from a DVR surveillance to Windows.

Hi,

Have a standalone DVR for surveillance and it has 1TB HD in it. I want to back it up to my Win XP.

I think it is Linux, but not sure. Whilst it is connected to the network okay as I get pictures on my ipad and iphone, I cannot see it in the XP Network explorer. I assume this is because it is Linux.

It does have a USB 2 port but they say for a Card which will not take anywhere near 1TB.

Any help to do this please?

Thanks

oz