A big problem about HTC G7 phone

[lynnband]

Hello,guys.I bought a G7 online , I think it's not expensive,so bought it.

But when I insert my SIM card in it, it always show "no SIM" , one day ago ,it stills show that, I had tried many times , can anyone help me ?
Thank you advance! If nobody can help me ,I just send it back to that site.

 

[Budza]

Probably network locked. Can get that fixed (for a fee), though if it's something else, it's stuffed...