How to disable- phone tracking in iphone 3gs -?

How do i turn off the mobile tracker in my iphone 3gs.

because, i'm currently facing the below issue.

everytime i insert a new sim in my iphone 3gs when i travel abroad, it sends out a message to a particular number and i get charged for international SMS for it.

how can i disable this.

was told there's some app available for it. Or is there any settings change to be made for this.

Erase all data and content, Iphone 4? Will I have to sync to Itunes?

So the iphone 4 i'm posting from right now was my aunts, she gave it to me. So it was logge into her information. I thougt i did what i would have to do. I can download apps from my apple id but when i ask to update all it prompts me for her password which i do not know. I'm planning on using the erase all content and settings function from the phone and i do not have itunes as i'm using ubuntu, i do not plan on restore all my songs and apps, will i have to sync the phone to itunes to be able to use it again

Windows xp can't find modem?

Ok pretty annoying night, I've been up for 6 hours trying to fix my laptop. I finally just went screw it and did everything over, restarted windows xp and got it running, I'm trying to get wireless Internet but it can't seem to find any of my modems, setting an Internet connection won't show any ports or anything. I have TWC and it's pissing me off, I'm on wireless Internet right now with iPhone but it won't show on laptop.
Any help connecting my modem to laptop would be appreciated.

Will an iPhone 4S sim work in a Nexus 4?

I currently have an iPhone 4S and my contract ends in 3 months.
I want to buy a Nexus 4 sim free but will I be able to use my iPhone sim in the device?
Also will my data plan for my iPhone allow me to use to Internet on the nexus 4 or are they different data plans?

Hack my 'Personal Hotspot' on my iPhone 4?

I just connected my laptop up to my 'personal hotspot' on my iPhone. I was using the wireless for a while and then went away. When I came back I noticed that it said: 2 connections. I'm the only person who is using the wireless. Is there any way that somebody else could hack it? How can I stop them?