Htc ozone frozen and won't shut off?

my phone was acting up - the screen wouldn't turn off when it wasn't in use, so i was going to reset it, and i hit power off and the screen went blank, but didn't turn off. i pressed the power on again and now it's stuck with the color wheel and at the top it says voicemd.exe and won't go anywhere or shut off.... how do i reset it/fix it???