Arduino UNO, all of a sudden can't upload programs

Development Tools IDE 1.x
1

Hey guys,

So my friend and I were working on a 3x3x3 LED cube, he was making the cube, and I was coding the arduino, so while he was making it, I used the arduino simulator to test out the code I was writing. When I was done, I uploaded the code, and we tested the cube, and it worked almost perfectly.

So I went to change one thing in the code, and I was holding the arduino in my hand, with the cube connected. And all of a sudden, it says it can not detect my arduino on COM4. So I go to Tools> Serial Port but it is greyed out.

So we went to his laptop and it was the same deal. He had an arduino, so we tried his and it worked fine it both laptops. The oddest thing, is that mine still runs the program it last let me upload, turns on fine, and Windows 7 (64bit) sees it fine.

I made sure the driver were up to date, and nothing was on pin 1 or 0. Any ideas?

2

Does the power led Lights on arduino board?
When you connect all the LED did you use a power stage on the output of the arduino.I mean did you take precaution about the amount of current all LED will drain?

3

Check the "Devices and Printers" icon in the control panel. You should have it listed there and it's properties will tell you the COM port its on as well as let you switch it.

If not, check the Device Manager under "Ports (COM AND LPT)" Make sure it isn't disabled and doesn't have any error codes.