I have developed a small application that uses 7 seg. display for output. I have used A/D Convertor that is interfaced with microcontroller.

I use a 'push button' that connects Vcc to reset pin. I have not use supervisor chip. When I switch on the power supply, the microntroller gets hanged. Pressing reset button gives an invalid output. So to get valid output I have to switch power supply several times and I am tired of doing this.

If a high on the reset pin moves the program execution to the beginning, what sort of problem do I am facing ?
Is it due to crystal osciilator or ADC ?