My arduino uno (purchase directly from uno store, not a bootleg) was working properly a few weeks ago.
Chip ATME-GA328P-PU
Mega 16U
Upon first install, I connected the uno via usb and the software installed automatically. I didn't have to do anything else.
I connected the uno today and it tries to install the driver, but fails.
On my Windows 7 machine, device manager shows other devices>Unknown device.
If I search automatically, it cannot find any drivers
If I browse my computer and search in "C:\Program Files (x86)\Arduino\drivers", it states could not find driver software even though the arduino.inf file is indeed there.
If I choose "Let me pick from a list of device drivers", I choose Ports (COM & LPT), choose have disk and browse
to "C:\Program Files (x86)\Arduino\drivers" and choose arduino.inf, then the arduino uno model.
Prompted with "Installing this device driver is not recommended because windows cannot verify that is is compatible with your hardware". Proceeding, software installs, but fails to start "This device cannot start (Code 10)
I tried different versions of IDE
I deleted all unused COM ports
Used another USB cable, made no difference
I tried installing on another machine (Windows8 ) with the exact same errors.
I don't have another UNO to test with, but here's what I've tried since my original post...
I tried connecting the UNO to 7 other machines (Mix of Win 7/8/10). None of them worked. So I contacted the arduino store. They wanted to know the status of the on-board LED when the board is connected to the computer. So I connected it, and wouldn't you know it, Windows installed UNO without a problem. Note there was nothing different connecting it this time that worked vs. all the other times I've tried to connect (using the same cable)
I do find that if I have the UNO connected for a long period of time on a Windows 7 machine, that device manager will eventually show the UNO as "unknown device". This doesn't appear to be an issue on Windows 10. I did update the driver on Windows 7 to the latest as I figured that maybe it was the old driver that was causing the unit to go to "unknown device", but that doesn't seem to have made any difference.
Furthermore, Arduino support had me do a loopback test for testing communication between computer and board. Test was successful. They also wanted me to do a DFU [Device Firmware Update], but it already had the latest revision.
So long story short, it's working, but very flaky.