Cannot get any sketches to upload.


I have never had a problem uploading sketches before, until today. The only thing I have done different today is use a different laptop (this one is a windows rather than mac). I keep getting this error message:

avrdude: ser_open(): can't open device "\.\COM1": The system cannot find the file specified.

I thought it might be set to the wrong port, but the port option in the toolbar menu is greyed out. I have also tried changing the programmer bit in the toolbar menu, but that has not worked either. Any ideas?

regards, Glen


Im also using a motor shield, I have never used one before. Do I have to use a motor shield library? could that be the problem?

I would think that your problem is driver related. Have a look inside the Device Manager to see if the drivers for your Arduino are properly loaded.

You can access the device manager by "right-clicking" on My Computer from the start menu. In the list that pops up you would then select manage which will open another window. From that window you will be able to open the device manager by selecting it from the list on the left.

Once inside the Device Manager you should be able to find the arduino under "Ports COM and LPT" if the drivers are correctly loaded. If not it will most likely be entered under "Other devices" in which case you will need to install the appropriate drivers.

Let me know if that helps, good luck.


I am having the same exact problem. It started about 2 days ago when I let windows install some updates. I am guessing that it has something to do with a security upgrade since the Arduino drivers are not signed by Microsoft.

I have tried everything that many people on this forum and others have suggested. For one thing I uninstalled the software and reinstalled the latest version 1.6.4. I clicked on the installer show details and the installer hung up for a LONG time on the line which said something like installing AMD drivers. When some time was up, I guess it skipped the installation. Bye the way, I don't have a true hardwire serial port like most people I use a USB port and the driver is a virtual Serial/USB port. I am not sure if the Uno would show up on the Device Manager as an item on the legacy hardware, ie. COM port or some place else.

I disabled windows checking for unsigned drivers and used the dpinst-amd64.exe, found in the C:/Program Files (x86)/Arduino/drivers folder to try to install them. It finished and said everything was OK. I rebooted and had the same problem.

This is a real mess and nobody seems to know how to fix it yet.

This is really a driver issue.

Looking for help!

I have Win7Pro, with autoupdates enabled. I use FTDI for interface chips I'd have to say exclusively, with a Duemilanove, and FTDI modules (FTDI Basic clone with micro USB connector, MIKROE-483 with mini USB) for my boards. With 1.0.6, I am not having any problems with complaints about drivers. Is that just a 16U2 problem?

I am not sure if this will be of any help or not. I take it that you are having issues with the new drivers, if so an archived copy of the "Old" Arduino Drivers can be found inside the installation folder on 1.6.4.

I am really unable to help more without knowing if and/or how the board is being registered by windows.

I looked into that folder and my zip file is empty as well as being corrupt. Hopefully we can get someone to post the old drivers.

"Other devices" in which case you will need to install the appropriate drivers. Hi SantinoPrice

Yes it is in 'other devices'. I've tried to load the appropriate drivers but the "Port" is still greyed out under 'Tools'. How to move the port from 'other devices' to 'Ports' is the question.

Win8.1 gives an error message that the last thing connected, the arduino board, is not recognized.

Well, I went to uni today and used Arduino Version 1.6.0 on Win7 and all worked fine. So I came home and downloaded 1.6.0 onto my Win8.1 and the Tools-->Port is still greyed out. In Device Manager the Arduino now registers under USB controllers as a USB Serial Converter. ?? Is it time to give up and get away from Win8.1?


Try again, the files were there when I downloaded. cheers


I uninstalled 1.6.4 then downloaded 1.6.0 and installed it as an Administrator. When the installer got to the com port installation it did not hang for what seemed like an eternity with 1.6.4 so I had high hopes.

I fired up Arduino and saw that it said my UNO was on COM 1. I exited the software and edited the preferences to COM3. Then restarted Arduino. It came up showing UNO on COM3, but the Tools Port was greyed out. I loaded a sketch and got this error message:

This report would have more information with
“Show verbose output during compilation”
enabled in File > Preferences.
Arduino: 1.0.6 (Windows 7), Board: “Arduino Uno”
Binary sketch size: 472 bytes (of a 32,256 byte maximum) Serial port ‘COM3’ not found. Did you select the right one from the Tools > Serial Port menu?











So I am no better off than I was.

I opened Device Manager and nothing about a COM port or Arduino shows up. From reading the forum, it looks like I need a Virtual Serial port, however I don’t know how to get it.

Can anyone help me figure this out?

Thanks in advance for your help!

@Techhack Can you please post a link to where you purchased your board, or inform me of the usb-serial chip that it uses. This is normally the chip closest to the USB port.

I need to know which driver is actually causing your problem.


The chip is about 0.25 inch square. As best as I can read the small print it says: MEGABU2 1039 9F4289

I hope I have everything correct since it is such small print.

The UNO was purchased from a friend so I have no idea where it came from.

I really appreciate your help!

The problem seems to be widespread. I cannot get any sketches to upload since about 5/15. Get error message "Launch4j". I have tried all previous versions of the code and nothing works. I'm using Windows 7. My arduino uno has worked just fine prior to this problem.

I think you must have the right drivers. In the release notes you may be able to find. These initial articles may help as they provide the details for Windows 8.1:


Well I have two issues. One since the Microsoft Update I ran ~ 5/15/2015, nothing shows up in Device Manager so I could manually install the correct driver. Two I ran several versions of the device installer and they showed everything was OK but no drivers were installed that UNO could find.

This is quite perplexing!

Thanks for your help!