Arduino Uno and serial communication via USB on Windows 7 64 bits


I have developed an application on an Arduino Uno which does serial communication via USB to a Visual Basic program. I developed under Windows XP and tested both under Windows XP and Windows7 32 bits. Everything works just fine. At the start of the PC application I can select the correct COM port and then everything works and communicates perfectly. I now sent the sketch and the Visual Basic program to a friend of mine who has Windows7 64 bits. There it does not work. He can select among the shown COM ports but doesn''t get any connection to the Arduino (I don't actually know whether the correct COM port is shown at all as I can not check for myself because he is quite far away).

Is there any known issue that the serial communication via a COM port (physical USB port of course) does not work from Windows7 64 bits?

If so, are there other Windows versions where this is also the case?

Do I have to make other ports than COM ports selectable in the PC application to get it to work?

Thank you very much for any answers.

I am on a Win.7.64 bit and have done the same with VB, C# and arduino and all works well. It might have to do with how you deployed the exe does he use visual basic as well?

does his arduino show up on the device manager?

furthermore does he have the driver for the uno installed?
because even though the arduino is recognized he has to update the driver

I deployed the exe as a completely standalone application. He doesn't have Visual Basic on his PC, I just instructed him to have all the .Net frameworks installed.

I'm quite sure that he has the driver installed, but I will check back with him. Also regarding the device manager.

What do you mean by "even though the arduino is recognized he has to update the driver"?

In any case, what I understand from your answer is that the COM communication via USB basically works under Windows7 64 bit. May it have something to do with his particular PC? I think there maybe needs to be some "component" in the PC to allow the conversion between serial COM to USB? Or is this not the case?

well when i got my uno it plugs and play just fine but i kept having issues untill i installed the Arduino driver that came with the ide.

look here :

I have had no issues with getting my arduino to work after the proper driver was installed. (win7 64-bit) Sounds like a driver issue to me. Either that, or the sketch wasn’t uploaded to the arduino properly, or the wrong comm was selected. Also verify the baud.