about windows and arduino uno r3

Development Tools IDE 1.x
1

system-Windows

board-Arduino Uno r3

wrong message(can't upload)-
avrdude: ser_open(): can't open device "\.\com4": the system cannot find the file specified.

I just running S4A... :confused:

then,
The light "L" not work.
(The light "on" ever work.)

I try to restart the board,
the light "L" is on,
but it goes out. (soon)

I'd check the Serial Port,
but it's not wrong.

I don't know what's wrong.

pls help me.

tks.

2

YufongGao:
I'd check the Serial Port,
but it's not wrong.

How do you know it's not wrong?

3

I check my SP in Device Manager in Windows.
The UNO R3 is linked to COM4,
my IDE is also linked to COM4.

4

What is "I just running S4A..." ?

Which version of the IDE ?

Have you tried with nothing else connected to the board ?

5

I running scratch for Arduino,
and then...you know.

v1.8.8

Yes, I tried.
It's also cannot connect the board.

6

I try to connect r3 on mac,
it's work,
but it still cannot connect on my pc

7

It's OK!
My PC's wrong is in usbser.sys!
I delete it and reinstall,
and r3 it's connected!!!!

8

Tere were some issues with bad versions of USBSER.SYS.
Not from Arduino I must add.

Two things are possible.

  1. It was just a bad driver from some other hardware you installed.
  2. It is a nefarious driver in which case you should do a full security sweep of your computer using reputable ONLINE scanners for antivirus etc.

I have seen both instances so you might want to go with option 2.