How to tether my nikon d3000 to my laptop?

I have a nikon d3000 connected to my laptop. I can downloading images and so on from the camera to my computer, but i do alot of remote photography. How can i make it so that i can use my laptop like a view finder, and see what i'm actually taking a photo of. (this would be useful since i can't be both in front of and behind my camera at same time. Any free applications would be helpful

Added (1). As a responce to fhotoace, i know this, thats why i'm asking for any alternative. I don't have the money to go out and pay for some of these other third-party apps which do support what i'm talking about, this camera was a gift which is how i could afford it. I'm looking for free alternatives.

Print size for a 14.2 MP image?

I have a nikon d3100, and i want to get a portrait photograph printed. Can anyone tell me what is the largest size I can get. I went to a print shop, and found that printing on canvas is costlier, but allows image sizes which are bigger than photo paper. Also, is canvas recommended?
I'd love to get a 15'X20' print… Possible?

Added (1). EDIT: Sorry, no no… I meant inches. My bad.
how about now?

HOW TO GET NIKON D90 KIT LENS TO AUTOFOCUS?

I changed it to a 50mm lens and it was fine

then when i changed it back to my kit lens it won't autofocus.

eg. When i half press it, there's no beep and it doesn't focus itself.

how do i solve this?

THE AUTOFOCUS SWITCH ON THE LENS & CAMERA IS ON A ALREADY

Added (1). The lens is locked in properly.
everyime i half press the shutter release button it says "r13" not sure whether that's related thou.

what should i set my metering/bracketing etc to be so it will auto focus!

Added (2). Yes i have removed the lens and put it back in. I reset all custom settings.still no autofocus

I bought nikon d3100 when i'm capturing photos i'm getting red tint?

Even though i selected auto mode still the picture is dull and getting red tint on the faces can any one guide me. Or is it my wrong selection to buy D3100

Looking for new DSLR camera, any suggestions?

Right now I have a Canon Powershot S3IS
It's okay, but sometimes the pictures are grainy, blurry, the focus is if-y. I'm just not 100% happy with it.

I've been looking at Nikons. I've been researching the nikon d3100.
Any suggestions?

I ONLY WANT OPINIONS FROM PEOPLE WHO HAVE DSLR CAMERAS, I DON'T CARE ABOUT YOUR POINT-AND-SHOOT CAMS.

How to HDR night photography #2?

Ok, i asked this question earlier and people are asking for my settings. My ISO=100 F@ 8, Shutter speed@ 16". I took some decent skyline shots like that without HDR and had no grain. But when I add HDR yes! So take multiple shots I'm hearing but how many? My Nikon D3100 doesn't allow bracketing so its all manual. So lets say I have to shoot 3 shots so my settings would be like this?

shot1: 8"
shot2: 16"
shot3: 25"? Please give me the best possible shutter speeds for manual bracketing! Anything helps.

Why is the Nikkor 35mm f/1.4 Way more expensive than the Nikkor 35mm f/1.8?

Also, the 50mm 1.4 is considerably cheaper than the 35mm 1.4 as well. Can someone please explain why? They both seem to have similar features, but I'm unsure why the prices vary so much. I'm looking into purchasing a new prime lens for my d60 as I've been shooting with my kit lens.It'll be used for everyday use so I can document my life and experiment, explore and expand with my photography skills, so any help with that is appreciated! Thanks!

Added (1). ALSO, I'm not very familiar with 3rd party lenses but I've been looking somewhat into brands like Sigma and Tamron, if you're familiar with prime lenses from them that have better value let me know!

My Nikon D3000 is running slow?

It runs really slow when it goes to view pictures.
Any ideas why?

Nikon D3000 memory card slot broken?

My camera which i recently got about a year and a half ago now will not take my memory card the nikon people told me to push on it and it actally broke my memory card. I got a brand new memory card thinking that maybe the one that broke was a little damaged to begin with and went to put it in and it still would not go in and the camera keeps saying that the card may be damaged and do not put it in. The card is not damaged. When i put it in it goes in but then its like something is blocking it and it will not stay in. Does anyone have any idea what might be wrong with it or if anyone had the same problem. Also if anyone know how much this kind of repair would cost i paid $700.000 for it and if the repair is going to cost alot is it even worth me getting it repaired or should i just go get a new camera? I really don't have the money to go out and buy a new camera right now but i do need a camera.

How to turn on auto focus mode on nikon d90?

Auto focus mode on nikon d90 sometimes gets deactivated and i have difficulty turning it back on