OK Try this. Download the Android Stock rom of your micromax device model to your pc from this site:http://mxrootrom.blogspot.in/2013/12/sto...-roms-for-all-micromax-android.html Then insert your sd card in a card reader and connect it to pc (Don't use device to read sd card,it may not work).Then create a folder named 'root' and move the stock rom(ZIP File) to the root folder in the sd card.Now insert the sd card into your device. Get into recovery mode and wipe your device and also remember you must wipe out the'dalvik cache' also. In the recovery mode,select 'apply update from sd card' and browse for the zip file in the root folder of your sd card and select the stock rom file. Now it will take time to install the stock rom on your device. Now all things are set right. Then reboot your device.Your device will function properly.
Android firmware may malfunction sometimes in Samsung Galaxy S duos. Uninstall unwanted apps from the device. Go to Settings->Application Manager->Select 'Running' Tab. Close unwanted process.because background process may slow up the device. Backup all your data and get into recovery mode and wipe the device or select factory reset in settings. Now,your device should work correctly.