In order to hard reset a Micromax A90s, you should perform the following steps.
Remember! Hard reset will delete all the data on your device; pictures, contacts, messages, apps and more.
Micromax A90s device will be brought back to the default configuration of a brand new device.
1. Lets get started. Begin by pressing the Power button to turn your phone off.
2. Next, press & hold the Volume Up and Power buttonsRecovery Mode menu will appear (unless it won't, in which case press Home button).
3. Using Volume and Power buttons, select the wipe data/factory reset option.
4. Now select Yes and Reboot System Now options.
5. The hard reset process is complete. Congratulations.