Android Studio doesn't recognize my device

Issue

Here is the problem. I want to run my Android Studio apps on my device (Samsung Galaxy Ace 2). But nothing works for me. Tell me what I've missed:

1) USB debugging is on

2) ADB driver is installed (in device manager i can see Android Composite ADB Interface)

3) ADB device list is still clear, even if i reset server(adb kill-server, adb start-server, adb devices - list of devices is clear)

4) in google usb driver directory, in android_winusb.inf file I added my device identificators

5) Android device manager still cannot connect to my device, showing this error when I reset it: "adb connection error an existing connection was forcibly closed by the remote host"

So I will be glad to hear any advices. Hope you'll help me

Solution

I am sorry that i bothered you all. The problem was my device is cloned in different places in device manager. It was gone when I tried to update driver for my phone in "Other devices" list, and before i have been updating it in wrong sections. Thank you all.

Answered By - Red Hot Chili Coder