I lost My Serial Port

Hi, I am New in arduino wold and I trip! Since Yesterday, I lost my Com3 (serial-port) I have Arduino Uno R3 . Got it before Christmas and until yesterday all was working Very Very Well. I am on windows 7, 64 bits. But yesterday… In the IDE, Tools, I have no more Serial Port (the name in french(Port série) is light, I can’t choice it. I change my USB cable, I try all my USB port. I change by 3 times my IDE. I connect and disconnect 100 times !!! No serial port, no com3 I read Help or the Trobleshouting, but not find answer.. Please, help. Thank you. René cléroult Baie-Saint-Paul, Québec, Canada

What is plugged into the Arduino, apart from the USB cable?

Yesterday, i have the circuit no.11 with the piezo.
But today, now, nothing.

Hi, This morning, I reinstall the IDE, I started Arduino.
And it is Working.
so, for now, I don’t know what was the trouble.

But what I can say : if something worked not like it is supposed to do, reinstall IDE first.

thank you for your help.
rené cléroult, baie-saint-paul, Québec, Canada