In Arduino program, under "Tool" the "Port" is grey so I can not change COM-port. How do I do to to get it black
What's the version of the IDE? Have you installed it with the installer? If not, have you manually installed the drivers?
This question will probably be a yes from you, but do you have the arduino plugged in to the computer? Also, provide some more details like IDE Version. Have you tried restarting the IDE.
Samuel