Default Help plz wifi doesn't work on HTC desire V after rooting

I tried to root my HTC desire V phone, and after i did successfully the wifi doesn't work , i tried every thing, "factory reseting" clear all data even formatting SD card still doesn't work, i've been searching on the internet for the past two days and some people called me it might be from something called "Kermel" i downloaded all HTC desire software and tried to flash the kermel but it required a file called boot.img that i don't have , i don't want the root anymore i just want my phone to have wifi as it always did , thnx in advance