Why doesnt the blue screen go from my htc 150 desire

[AC Question]

hi, I was just on my HTC 150. Desire, I was messaging my friend on whatsapp until my phone just randomly turned off, then it turned into a plain blue screen and keeps powering off and on and showing that blue screen every 1 min, I tried everything to remove the blue screen by rebooting, taking out my battery and my simcard, but it just won't go, any ideas how to fix it?