Why don't Turkey, Iran, or Russia just wipe out ISIS?

This is the big question on everyone's mind because each of these countries could literally wipe out ISIS completely from Syria and Iraq within 3 to 4 weeks if they actually wanted to.

Let's start with Turkey because this is the most interesting reason.

Turkey is Sunni Muslim and so is ISIS. The main reason Turkey doesn't just wipe out ISIS in 3 or 4 weeks with their army is: "ISIS is seen as a potential means to an end". And that end would be potentially the end of Assad who is persecuting Sunnis in Syria and though this isn't talked about, "The end of the Iraqi government that is also persecuting Sunnis". So, Turkey doesn't attack ISIS and many ISIS people live or visit or recruit in Turkey for ISIS and this is allowed presently for these reasons.

Next, Iran:

Why doesn't Iran just sweep in and take out ISIS in Iraq and Syria?

This is fascinating too because I have no really good reason why they don't do this.

Then why doesn't Russia sweep in and wipe out ISIS?

At present this is not their goal. Their goal is to wipe out democratic opposition to Assad only.
However, ISIS is pissing off Russia more and more each day. However, Putin can completely control the media in Russia so anything he doesn't want in the news won't be there. So, in the end it is whatever he wants to do. And right now he wants his warmwater port of Tartus so he wants Assad to stay in power. Also, there are still up to 50,000 Russians living in Syria many married for 20 or 30 years to Syrians already. So, there is some interest in keeping this "Russian Colony" in the same way sort of like a modern day "Cuba" in the Middle East with Assad continuing to rule there.

Why doesn't the U.S. and NATO wipe out ISIS?

This is more political at this point than anything else. It also has to do with the trillions the U.S. and NATO put into IRaq and Afghanistan from 2003 to the present. Nothing really has changed much in Iraq except now the government is representative of the majority Shiite population but the problem with this is it is now de facto an Iranian state.

So, the main reason the U.S. doesn't go in and wipe out ISIS is because we screwed up the area by going into Iraq and Afghanistan already and wiped out all balances of power that might have prevented ISIS now by killing Saddam Hussein and Qadhaffi who would have stopped ISIS in it's tracks years ago now if they were still alive.