Cannot access hdd
I just installed debian(gnome) in my system. In doing so, I used the guided partitioning. Now I lost all of my data. Now i'm trying to recover that using photorec. I have testdisk file(tar.bz2) but I don't know how to install it. And I cannot access internet. While booting it shows 'failed to bring up eth0' and 'SIOCADDRT no such process'. Now I'm writing this from a debian(kde) live cd. I tried to install test disk but it says I don't have the permission to access the hard disk. I tried changing the permission to the hdd from the installed OS, but there also it says that 'unable to change permissions'.
Please help me...