Runtime error: No USRPs found on interface eth0

Hi
I am using UHD API and facing the problem, in-fact my PC
has gigabit ethernet interface still it gives an error No usrps found on
interface eth0 when run the any file except those files which start with
uhd.

Any advice or solution for this problem…??

One more thing is that when i run uhd_find_device.py and
uhd_usrp_probe.py files it works fine without any error. why this so
happening???

I have burn the images of UHD not raw ethernet on sd card. I this the
problem???

Please help!!!