i do have tethering on one and dont on 2 others. your pc should recognise. heres what i will do,its late tonight,but tomorrow i will restore one of them and try again to compare. i have documented everything i have done very well, so if i cant get a port again after restore i will search my notes and post the results,also i will try on a different pc as well,but i will say that i could not get it to show up until i dialed the dm codes.having said that the pc i am using is a dedicated for iphone only pc that i have used for a year,i dont keep anything but iphone softwares ect. on it,and i mean it has about everything on it that has been out there in the last several years for i-devices,having said that i did plug one up to a desktop pc at the store today and it did show up. i will see if i can come up w/something tomorrow.