Why does my SIm card not work on my iPhone?

So anytine I put any kind of SIM card in my iPhone, it says there's no service? I got like a warning that if I don't restore my iPhone I will not be able to receive or send calls? And plus I don't have iTunes so would I have to rest it or is that a completly different thing from restoring?

Is resetting an iPhone the same as restoring it with iTunes?

So a few days ago i got a message on my iPhone that if i don't restore my iPhone then I won't be able to receive or send calls and I can't do that either. I looked on youtube on how to restore an iPhone and it said you needed iTunes but I don't have iTunes on my computer. So would restoring my iPhone with iTunes be the same as resetting it?

How to replace the songs on an iPhone 5?

I have previously synced my phone with another computers music, but I've gotten a new macbook air and downloaded my songs on here. When I tried to sync the iphone 5 here the songs didn't convert. I'm probably just stupid, I know zilch about computers. But I'd really appreciate the help.

Problems with Facebook on the iPhone 5?

I recently brought an iPhone 5 and on my computer i choose not to share my status with certain people. But on my iPhone when i update a status its still on the 'Custom' option but lets people see my status. I was wondering how i would configure with those settings on my iPhone

How to make my iPhone 4 vibrate and ring?

I have a iPhone 4 and I've had it for about 3 years now. About 1 year ago I dropped it in the snow so it got water in the headphone thing but the headphones still work. For a year now my phone hasn't vibrated or ringed. It plays music, but when I get a phone call, text message or any type I notification, it stays doing nothing. I know about the ringer control, I've tried, fiddling with that but still nothing. About 9 months ago the ringer control kept flicking by itself and then it stopped working, it does look at bit dirty inside so I may need to clean it. I don't really Particulary want to go to apple but if I have no thee choose how much would it cost?

Can you put a cut sim card into the old sim card slots?

I have an iphone 5 and my sim card is cut down to fit into it. I want to be able to use my sim in my old nokia brick phone as well though because i'm attending a heavy metal festival next week and don't want my expensive iphone to get wrecked in the mosh.

Just wondering if its at all possible.

Why is the YouTube on my iphone so slow?

I have an iphone 4s and the youtube app is so fricken slow! It takes at least 10 or 15 minutes to load a video of about 5 minutes and anything longer than that I just give up. I thought this phone was suppose to be great being it has 4g but honestly my iphone 3 went quicker than this crap. Why is this happening!