Driver installation problem for UNO on windows 7 32 bit (Laptop PC)

I was trying to install drivers for Arduino UNO on my laptop having windows 7 32 bit. But every time i plug in the usb cable I got the message that the device driver didn't install successfully. I have tried installing them explicitly through the update driver option in device manager but still the windows was unable to install it giving a message of an unknown problem (code: 27). Surprisingly the drivers are installed on first attempt on my desktop which also have the same operating system (i.e Windows 7 32 bit).

Is there anyone who can help me installing UNO on my laptop?

You need to google CH340 and install the drivers.

These are for CLONE Arduinos and are not included with the IDE.

If its a GENUINE arduino the drivers are in the drivers folder of the IDE installation.

@Ballscrewbob installing CH340 did not help, but what new happened after it's installation is that before the IDE's port's section is showing only COM3 and COM4 but now it is showing some other COMs as well such as 5,8,19,18 etc. However the device manager directory is showing that arduino is connected to COM6 which is still not in the list of the ports, IDE is showing.

And just to confirm, I am using Arduino clone.

Sounding like you have a messed up hardware list and possibly drivers from things you may not need.

Windows is pretty bad at keeping a list of com ports and often adds them when it doesn't need to.

My own POV would be to remove all unused com ports and the IDE then do a major clean up and start again.

Google "remove unused com ports" to start with before you go too far. Probably leave COM 1 as most computers still have a COM port.

Don't plug any Arduinos etc. in whilst removing unused ports.

Move your sketches folder somewhere safe if you want to keep it.

Uninstall the IDE properly using the add remove software.

Remove any other unwanted software at this point eg. odd driver packs you may have installed that didn't work anyway.

Start a clean up (Steps here)

Grab a copy of IDE 1.6.12 and start again.

Did everything you said but still not working. This time the only difference is that the additional COMs that were showing in the ports tab of the IDE are not showing now but the Arduino’s COM is still not there.

Can you list each step of what you did and the order you did it ?

So I can see if I missed something.

First of all I uninstalled arduino from my PC, then I installed the CCleaner and deleted the only driverpack I had, deleted all the residual data it has analyzed and fixed all the registry issues it had pointed out. Then I uninstalled/deleted additional COM ports by running Device manager as administrator through command prompt. Then after restarting in the hope of success I downloaded and installed the IDE 1.6.12. But again COM6 (the port arduino is plugged in to) was not found. Then I installed the CH340 drivers for 32bit again, but still nothing happened. Thats all I did before reposting here!

OK there was a step or two missing that you didn't do.

"There may also be an Arduino folder that gets left if you are on windows.
The path normally used would be

Also did you move your sketches folder somewhere safe ? (you can put them back where you need them later)

You would have done that at around the same time you ran WISE registry cleaner that is also mentioned.

I know it is a PITA but there is method to my madness in doing some things a certain way and getting a clean start to an issue is usually a key factor.

Get the CH340 drivers HERE

Have you looked at the chip to confirm you have the CH340 chip ?

If the driver is correctly installed you should see it in device manager.
It will have CH340 in the name , if it just says COM X or USB port it did not install correctly.

I had this yesterday and it took several hours to get it right.
Made worse by the fact that the clone had a mini rather than micro USB connector which i had to buy.

You may have to install the driver manually.


There was also a problem with non kosher FDTI chips iirc.

Identify the chip you have first.


I only use a Workstation these days for Arduino,
I found laptops generally to be problematic for installing several programmes but never worked out why.
The version of windows did not seem matter just a PITA getting stuff to work.

I did not get any thing new in the device manager after installing CH340 drivers. So probably either they are not installed correctly or the board might not have CH340 chip as you have mentioned.

And how can I just install the driver manually?? I have been trying each and everything which I knew since 2 days, and this obviously includes installing the driers manually!

And how can I identify the chip? It has written:


on it. That's all I know about the chip.

Take a decent picture of the chip near the USB connector and post it.

Other drivers suitable for the board are in the Arduino installation folder in a folder called DRIVERS.

If you are on X86 the only use the ones in the x86 folders.


There should be two chips , on is the processor and one is the USB intrface , post pix of both or the numbers on both if you can read them

Another thought, it can be difficult to read so look at the device manager on the pc it did install on.
It should show the ch340 driver if it is needed.


Device failure - No Valid Log configuration
This code means that the portion of the Registry describing possible resources for a device does not contain valid entries. For example, the device is marked as configurable, but the configuration information in the .inf file is set to hardwired. To resolve this error code, use Device Manager to remove the device and then run the Add New Hardware tool in Control Panel. If the device still does not work, consult the hardware manufacturer for updated drivers or further assistance.