This worked for me to solve the "Can't select serial port" problem I was having with my Uno.
I'm using Windows 7 64bit.
This site had exactly what I needed: http://www.arduino.cc/en/Guide/Windows#toc4
Here's what it said about installing the "drivers" for the Uno on Windows 7 (something I either forgot I did when I using my Duemilanove or just never knew):
Plug in your board and wait for Windows to begin it's driver installation process. After a few moments, the process will fail, despite its best efforts
Click on the Start Menu, and open up the Control Panel.
While in the Control Panel, navigate to System and Security. Next, click on System. Once the System window is up, open the Device Manager.
Look under Ports (COM & LPT). You should see an open port named "Arduino UNO (COMxx)"
(scobot - I could not find "Ports (COM & LPT)" but I found the Arduino Uno under "Other devices" - but after following these instructions I now have "Ports (COM & LPT)" in device manager, with Arduino Uno listed.)
Right click on the "Arduino UNO (COmxx)" port and choose the "Update Driver Software" option.
Next, choose the "Browse my computer for Driver software" option.
Finally, navigate to and select the Uno's driver file, named "ArduinoUNO.inf", located in the "Drivers" folder of the Arduino Software download (not the "FTDI USB Drivers" sub-directory).
Windows will finish up the driver installation from there.
When you launch the Arduino environment to do your programming, you should be able to access TOOLS>SERIAL PORT. Select whatever port is listed. I only had one choice, COM4.
Sorry to keep prolonging this thread, but I'm also running Win 7 64-bit on an HP Pavilion dv7. I also have a Toshiba Satellite T215D with 64-bit Win 7 and it shows the same results, so it isn't specifically the computer that's the problem.
I'm trying to get started with Arduino, I have a Uno board and am running the 0022 IDE. When I plug the board into a USB port, the power light glows green, and the pin 13 ("L") LED flashes yellow. The Serial Port selection menu option is grayed out.
When I go to Device Manager I see no Port options; the Arduino device does not show up at all. If I plug the USB cable into each of the USB ports there is no change to the Device Manager listing. I see no "Other Devices" option.
I've used the Action -> Add legacy hardware menu option to create three communications ports, COM3, COM4 and COM5. The system claims to have loaded the proper device drivers, but I've also right-clicked on each port and made sure that the system looked at the Arduino UNO.inf file.
When I examine the device status of COM3, I get this message: This device cannot start. (Code 10)
When I examine the device status of COM4 and COM5, I get this message: Windows cannot determine the settings for this device. Consult the documentation that came with this device and use the Resource tab to set the configuration. (Code 34)
I've set the serial.port value in the Arduino preferences.txt file to COM3, COM4 and COM5 in turn, and each time I try to upload the Blink example I get this message:
processing.app.SerialNotFoundException: Serial port 'COMx' not found. Did you select the right one from the Tools > Serial Port menu?
at processing.app.Serial.(Serial.java:153)
at processing.app.Serial.(Serial.java:76)
at processing.app.debug.Uploader.flushSerialBuffer(Uploader.java:75)
at processing.app.debug.AvrdudeUploader.uploadViaBootloader(AvrdudeUploader.java:93)
at processing.app.debug.AvrdudeUploader.uploadUsingPreferences(AvrdudeUploader.java:56)
at processing.app.Sketch.upload(Sketch.java:1603)
at processing.app.Sketch.exportApplet(Sketch.java:1568)
at processing.app.Sketch.exportApplet(Sketch.java:1524)
at processing.app.Editor$DefaultExportHandler.run(Editor.java:2293)
at java.lang.Thread.run(Thread.java:619)
And, of course, throughout all of this, the Serial Port selection option remains grayed out.
That was the next tack I was going to try. I have a couple netbooks running Windows XP, so I'll load up the Arduino IDE and see if I have any more success.
I also have some Arduino-like boards that I'll try with the Win 7 machines and see if I have more success.
I downloaded Arduino-0022 and installed it on a netbook running Windows XP SP3, then hooked up the Uno. Same results, or more correctly, same lack of results. No indication that the board is connected, no ports in Device Manager, no attempt to load a driver. I disconnected the board and swapped in a new CPU, then hooked it back up to the USB port. Still no joy.
So apparently it's the board, probably the USB chip.
What's my next step? Is the board still usable by programming using older techniques (like the ICSP connection), or do I salvage the chip, toss the board and get a new one? Or get a new hobby?
It's definitely the board. I got a new Arduino Uno and followed the directions in "Getting Started" (per scobot above), found the Arduino Uno listed under "Other Devices" and installed the driver software. When that was done I uploaded the Blink example, then changed the delay time from 1 second to 3 seconds and uploaded again. Everything works just as it should.
So now the question is the same as before: What do I do with the bad board? Is it still capable of being programmed, or should I just salvage the chip and any other removable parts, cut my losses and move ahead?
krell: if the board never worked (and the other board works with the same setup), it's probably defective in some way. You should return it to the distributor you bought it from for a refund.
Good luck with that one! Most are reluctant to take back electronic items once they leave the store! I found out that there have been lots of Arduinos that got bad bootloader files loaded onto the Atmel chips. No bootload or bad bootload = no communication?
All of our distributors should accept returns of defective boards. I believe part of the agreement for becoming a distributor. In general, there's a low defect rate for the boards but in the rare case that someone gets a bad one, we want to make sure it gets replaced. Let us know if you have any problems.