I recently got an arduino uno r3 and uploaded the blinking sketch. Everything went swimmingly. Now, a couple of days later I bought some things to start a project I had in mind, came home wrote up a small sketch to test out some LEDs but it won't upload to the arduino. The arduino lights up and executes the first sketch, but when I try to upload the sketch I get an error saying that the arduino is not connected to COM port 14 which is the same usb port I used last time. I'm on Windows Vista, and tried reinstalling the drivers and the enhanced arduino environment but nothing works. Also in Device Manager nothing comes up when I plug in the Arduino. I found this website http://blog.ethanfrei.com/2011/10/arduino-uno-revived.html
on another post but am not really sure if this is the problem. Any suggestions?
TL;DR- Arduino Uno R3, can't upload, Error no arduino Com Port, Windows Vista, reinstalled drivers, all lights work, runs last sketch, other post said might be ATmega8u2.