Default need help flashing rom

i have micromax canvas 2 and using sptool v3.122 (i think its most suitable version with my phone)
when i click dwnld after red bar completes 100% it showing me error
plz help

also i dwnloaded ROM from one of the xda thread but it contains only one .img file i.e. BOOT.img so cant use 'firmware upgrade' option as many .img files (except Boot.img) are not there
so will u give me link to new rom for jelly bean
plz explain step by step as i am new to all this stuff