Missing port

New at arduino. I successfully uploaded Blink and it worked for a while. then something changed and I could no long upload and got an error message saying com4 was missing . Checked device manager and there is no ports as there was when I first ran Blink
I have reinstalled Arduino and still no com4. Using Arduino uno. Please help. Thanks
Please email dfranklin@canadianinpressions.ca

This is probably flaky behaviour from windows, not your arduino.

I used to get this a lot.

Try restarting your computer.

when you connect your arduino to the computer, go to control panel and then device manager. If you look at the list of devices, you should see the arduino there, and which serial port ( or emulated serial port ) it is connected to. Make sure the same serial port is selected in the menu of the arduino IDE. Mine seems to change randomly from com3 to com4 for no obvious reason.