I am writing this guide for people who commit mistake while flashing firmware through SP TOOL and suddenly stopping it in the midst when the firmware is flashing to your phone.
Points to be noted :
1) Once u start download of firmware don't interrupt it in the middle by pressing STOP button. If you do so your phone will not start up & also when u try to flash it again through SP tool it won't detect your device saying no driver and device not detected.
2) Don't worry if you have done so and fear that you have bricked your device completely. All you have to do is not panic and follow the below steps.
1) Download USBDeview from the following link
32 bit - http://www.nirsoft.net/utils/usbdeview.zip
64 bit - http://www.nirsoft.net/utils/usbdeview-x64.zip
2) Now open it. It will display a list of all drivers installled in you system. Uninstall drivers related to mediatek. ( U can figure them out easily. This app will show the names of all drivers ). The driver names would be of the following. Mediatek USB Vcom, Mediatek preloader, Android ADB etc. Uninstall all of them by right clicking them and selecting Uninstall. Now close the app and restart system.
3) After restart now connect your bricked phone and install drivers. ( Go to device manager and add the driver file as you do normally )
In case u forgot how to install drivers here is a small guide for it ( http://forum.xda-developers.com/show....php?t=2180436 ) Thanks to bhargav1991 for the driver thread.
Win 8 users don't forget to turn off Driver signature verification.
4) Now u should see drivers installed successfully. Now open SP TOOL load the scatter and again connect tour device. BOOM ! Now your device should be detected and firmware will start flashing. Now ur phone is back
Let me know if you face any issues in this. I will be always glad to help you in this regard.
Hit if i helped you ! It doesn't cost you to hit thanks.