Procedures to hard reset HTC One A9.

Method 1

Step 1
Hold down the Power key for a few seconds to switch the gadget off.
Step 2
Press and hold the Volume Down + Power Key at the same time for few seconds.
Step 3
When you see the three Android pictures, release the held keys.
Step 4
Press Volume Down to choose “Recovery” option. Press Power Key to affirm. Choose “wipe information/factory reset” from the recovery mode using volume button and Power button to affirm.
Step 5
Pick “Yes ” to affirm the entire operation. All the data will be reset
Step 6
After that select choice “reboot system now”.
Now the work is done.

Method 2

Step 1
Hold down the Power key for several seconds to switch the gadget off.
Step 2
Press and hold the Volume Down + Power button at the same time for a few seconds.
Step 3
Release the held keys when you see the three Android pictures.
Step 4
Press Volume Down to choose “factory reset”, and press Power button to affirm.
Task is now complete

Method 3

Step 1
If the screen is off, turn it on.
Step 2
From Main Menu go to Settings and tap Backup and reset.
Step 3
Select Reset phone and select Erase all information.
Step 4
Tap OK to start the entire operation.