When I first got my Arduino UNO, I plugged it into my machine, running Windows 7 64-bit.
The laptop did not recognize the Uno as a device being connected. I had to disconnect and reconnect a few times then it worked for about ten minutes, but then Windows 7 stopped recognizing it. I restarted my computer a few times, but this didn't fix my problem. So I decided to try it out on my Windows xp 32-bit machine.
I installed the UNO driver in Device Manager, and it never worked and windows xp still has not been able to recognize that a new device is attached. Then, I tried another Windows 7 (32 bit this time) machine. I tried to install the drivers in Device Manager, but the Arduino did not appear.
On rare occassions the device will appear on the Windows 7 64bit machine and I can upload code from the IDE. So I have been uploading code when ever it is recognized and disconnecting the device. Just example code for now. As long as I do not leave it connected it usually will reconnect. I just got the uno a few days ago and it has been acting this way from the beginning. I would like to be able to eventually write output to the monitor but will not be able to do this is the connection fails randomly. It seems as though there is a hardware issue with the Arduino because i have no issues with any of the computers' usb connections with any other devices.
I am able to upload sketches to it for about 10 or 15 minutes, and the Arduino IDE stops giving its serial port (COM3 on Windows) as an option. The Arduino is still receiving power from the computer.
Primarily I connect the usb cable to the computer and Uno the computers do not recognize the usb device. In fact 95% of the time it is as though i have connected nothing because the computers do not see the device
The reason I thing the Uno may have and issue is that it does this on 4 different machines. I cannot upload code or select a com because the software will connect only to a device recognized as being installed.
I have changed cables, as well as connecting to several macines. What do you suggest I try to resolve this problem of both the connection dropping and the connecting not ever being established?
Thanks

