I've been trying to follow this tutorial on using the DS18B20 temperature sensor:
however, I can upload the program to the Arduino when it's not hooked up to the circuit. But when it is my computer does recognize the device and I can't use the serial monitor. It says it cannot find COM3.
My temperature sensor also got very very hot so I might of fried it which could maybe explain why its happening.
Indeed - a sensor that measured its own selfheating would be entirely pointless. Sounds like you connected it wrong. Always check and double check pinouts before applying power, its a lot cheaper!