To detect arduino there must be arduino drivers install in your PC. Sometime you have to install drivers manually. I am going to show this using Windows 8. But same steps are valid for Windows7, vista and XP. You must download Arduino IDE must first.
Plug your Arduino board in to PC. Sometimes PC will detect drives automatically. If not follow these steps.
1) Plug your Arduino board in to PC. Go to System properties and select Device Manager.
2) In this there is a Unknown device. Because still we didn't install arduino drivers.
I am using Arduino Mega 2560 board. I will show on this. Make sure to remember COM port number. later it will important when use Arduino IDE. In this case it is COM3.
See you in the next tutorial.