Hi,

If your phone has high end specifications and still you are experiencing lags/hanging problems. Then all you have to do is “Hard Reset”.

Before Atempting the Above Step Please make sure that you have backed up your essential data to some other external device.

Steps to Perform Hard Reset

There are 2 Methods to Perfrom Hard Reset

Method 1:

1. First switch off the device by holding the Power key

2. Then press and hold “Volume Down+Power button” at the same time for a couple of seconds.

3. You should release the keys when the Boot Mode screen appears.

4. In Boot screen select option Recovery, by using Volume Down to scroll and Volume Up to confirm.

5. When an Android Image displays on the screen press the Power button to enter Recovery Mode.

6. Press Volume Down to choose "wipe data/factory reset", and then push the Power button to confirm.

7. Select "Yes--delete all user data". Use Volume Down button to scroll and Power key to select.

8. To restart the phone, select "reboot system now"

9. You have sucessfully reset your phone to original state.

Method 2:
 

1. If the display is off, press the Power button to turn it back on.

2. Navigate to Andorid Settings

3. After that select “Backup&Reset” and tap Factory data reset.

4. Choose Reset Phone.

5. Select Erase everything to confirm the whole operation.

6. This process will take 2-3 minutes depending upon phone specifications.

7. After this your phone will be resetted to its default state.

As per the scenario you should go for Method 1 as your phone is lagging and hanging while operating.