Windows Vista resets Arduino Uno

I just received my Arduino Uno and installed it on my Windows Vista laptop. Installation went ok. However, I notice that the board resets constantly. Here's what I see; I wrote a simple sketch that runs a counter using a 7 segment led. When the sketch starts, it counts from 00 to 60 and it stops. There is a button that when pressed begins a countdown sequence from 60 to 00. That's how the sketch is supposed to work. But, if I don't do anything with the board, after 1 minute or so, the display goes back to 00 and starts counting to 60 again. I thought that there was a problem with the board, but I installed it on a Windows XP machine and it works fine. It starts, counts up to 60 and then it waits for the button to be pressed.

Has anybody else noticed this with an Arduino Uno using Windows Vista?

If in windows xp does not happens maybe is something related with power economy features in Vista, or some interaction with other usb->virtual com device, or a physical problem with the usb port (maybe vista vs. xp problem is just a coincidence)

What's happen if you test the program without entering to Windows (for example from bios setup)?

I just tested it again. I only applied power to the laptop running Vista and the Uno is working fine. But when I login, the problem starts happening again. I will look at the power saving settings.

Search for USB power options, or in the Arduino com port power options. Don't let Windows to turn off the usb port.

Anyway, your problem is very strange because I had those options by default and I haven't experienced issues like yours

The fact that it occurs when you log in is the big clue.

There is some piece of software running in the background that is polling serial ports. When the Arduino's virtual serial port gets polled, it resets.

Look through your list of running processes. Software for things like Verizon or Sprint data cards are usual suspects.

Hi,
Might be a bit late replying to this post but I had a similar problem.

As previous post mentions, I found that "Sony PC Companion" installed on my machine for my cell phone was opening the port causing the reset problem.

Try closing applications in the system tray until the problem disappears...