How to restore an iPhone 4s? - 1

First off, this isn't mine. I was helping my mom clean her room and we found an iPhone in perfect condition, almost like brand new. She said that she didn't want it, so she said I could have it. It was dead, so I put it on the charger and the "Hello Slide to set up" screen came up. I got as far as putting in my houses Wi-Fi and then it says "Activate iPhone. This iPhone currently is linked to an Apple ID. Sign in with the apple ID that was used to set up this phone. Message from owner…" I obviously don't know the owners information. I guess now the only thing I need to do is restore it, but whenever I go on iTunes it just shows the "Activate IPhone" message and tells me to put in the information. I'm just trying to restore this so that I can make the phone my own. I've tried the power and home button thing but it's just doing the same thing. Help please?
By the way, if you have anything mean to say, please save your time and don't bother commenting. And if you're just going to say i'm a thief, please don't comment. But for those of you who can provide help, please and Thank you So MUCH!

If the phone is running iOS 7 and is locked with Activation Lock, which sounds like the case, you must have the apple ID password associated with the phone to unlock or restore it. This feature was introduced to deter theft, so that a stolen phone could not be resold. Sorry!

Just keep it plugged

It seems the problem can't be resolved by restoring the iPhone.

To unlock the phone, you have to know the key or apple id associated with the iPhone.

However, I know an iPhone restore tool on http://www.recovery-ios.com/. I used it for my damaged phone, but I'm not sure if it can work with a locked iPhone.

Yes, you can try to use Recovery Mode to fix this problem. The tool Tenorshare ReiBoot is the best and quickest tool to enter and exit iPhone Recovery Mode. Without connecting to iTunes and holing home and lock button, without restoring your iPhone. Just one click, you can enter or exit Recovery Mode within minutes. Copy the link in the below to get the free download.

http://www.tenorshare.com/products/reiboot.html