I fixed my service tag I found it in 23.img I opened it with hex editor read my service tag from the flap and copyed it to the file then saved it then flashed it with nvflash hope this helps someone

My Phones Are:-

HTC One X : ISC Stock 4.0.4 Unlocked Bootloader & Rooted
Motorola Razr I : ICS Stock 4.0.4 Unlocked Bootloader & Rooted
Orange San Diego : 4.0.4 Rooted Stock
My Old Phones android Are:-
T-Mobile Pulse Mini > ZTE Racer > ZTE Blade > HTC HD2

My Old android Tablets Are:-
Dell Streak 7 16GB WiF > Archos g9 8gb > Samsung Note N7000 > Samsung Tab 2

Don't Forget To Say Thanks If I Helped You