Wednesday, April 08, 2009

Prolific USB to Serial Adapter Cable Drivers for Windows 7 [u]

I recently purchased a USB to Serial adapter cable (from MX-MART) for my MacBook (running Windows 7 Beta 1, via Boot Camp) to control my Uniden BCD396XT radio scanner. Since the control cable that came with my radio is a 9-pin serial data cable, and my MacBook does not have a serial port, I had to purchase the adapter. However, when I tried to install the downloaded drivers in Windows 7, it gave me a message saying, "Device driver software was not successfully installed." I right-clicked on the device in Device Manager and selected Upgrade Driver... and browsed to the path of the driver. After selecting the appropriate path, Windows 7 thinks for a minute and then displays a window saying, "Windows found driver software for your device but encountered an error while attempting to install it." Further down in that window it says, "USB-SERIAL CH340, Access is denied." I also tried downloading the latest drivers from Prolific's web site (Apparently Prolific is the manufacturer of the chip inside the USB-serial adapter cable), but those also failed. I'm not sure why Windows 7 has such a hard time installing this simple driver that apparently works well on Windows Vista.

I e-mailed MX-MART's customer support and very quickly got a helpful reply with an attachment that had a new version of the driver for Windows 7. After installing the driver (and answering "Yes" to the prompt asking you if you want to install an unsigned driver), the USB to serial adapter cable works perfectly and I'm able to program my BCD396XT scanner radio using FreeSCAN. Hopefully this will work for other folks who may be having trouble with the drivers for their USB to serial cable in Windows 7. Download the driver (145KB)

UPDATE (4/9/2010): A scan of CH341SER.EXE which is contained in the ZIP file provided by MX-MART with VirusTotal reveals the possibility that it might contain a Trojan. I have contacted MX-MART demanding an explanation and until further notice, I have removed the link to the download. I highly recommend purchasing the IOGEAR GUC232 USB to serial adapter, as it is designed to work properly with all versions of Windows 7 and below (both 32-bit and 64-bit) without having to install any drivers. I no longer use the Prolific-based USB to serial adapter that I purchased from MX-MART.

UPDATE (6/29/10): MX-MART claims that there is no malicious payload in CH341SER.EXE, and most of the major AV vendors do not detect anything malicious in the file. I myself have also run the driver installer on Windows 7 x86 when I used the adapter mentioned above and noticed no suspicious processes or open network sessions. I have had some requests to re-post the link to the driver (available above). Please proceed carefully at your own risk.

32 comments:

Anonymous said...

Thank you for sharing...

Sean said...

You are using a 32 bit version, correct? Your drivers are not working for me under 64 bit windows 7. This sucks! I have been so impressed with every other aspect of 7, except for this piece of junk. I think i'm just going to have to break down and buy a pci-e serial card.

Brian said...

I was using Windows 7 32-bit when I posted this. I have since upgraded to Windows 7 Professional 64-bit. Unfortunately, MX-MART does not provide 64-bit signed drivers for this adapter. You can temporarily turn off 64-bit driver enforcement by entering the following commands into a command prompt run as Administrator:

bcdedit.exe -set loadoptions DDISABLE_INTEGRITY_CHECKS
bcdedit.exe -set TESTSIGNING ON

Reboot and you should be able to use the 64-bit drivers that are included in the above file. You may also have to sign them using the Driver Signature Enforcement Overrider tool.

Anonymous said...

I'm still getting driver install failure. Frustrating.

Dave

Anonymous said...

I have Windows 7 (64 bit) and I can not get my Prolific based usb-to-serial to work. I always end up with a Device Manager error: "This device is not configured correctly. (Code 1)". I tried running the CH341ser.zip and that doesn't help either.

Abe

Anonymous said...

I am running Windows 7 (Build 7600 64-bit) and I can not get my Prolific based USB-to-Serial cable to work. I always end up with the following Device Manager error: "This device is not configured correctly. (Code 1)".I also tried installing the ch341ser.zip file and that did not help because when ever I tried to manually update the driver by pointing to the folder created by ch341ser then the Device Manager states that the most current Prolific driver is already installed.

Abe

Barry said...

Hey Abe,

I had the same problem. I removed the Prolific driver by running the Prolific install program again. Then, I opened the Device Manager and plugged in the cable in each USB port. When the device appeared in the list with the "!" icon, I right clicked and selected uninstall. I did this for all four ports on my laptop (Acer 5610Z). Then I removed the cable and ran the install for the CH341SER. After that, I plugged the cable into the USB port and it worked.

Dean Barnes said...

Amazing! I was tearing my hair out trying to get a Prolific device to work on my Win7 laptop. The drivers you host finally got the job done. Big thanks!

Anonymous said...

You are my hero! Spent half a day yesterday trying to get this to work! Thanks!!!!!

Anonymous said...

Thank you so much! I am using Windows 7 Starter (32-bit)on an Acer Netbook. Works GReat!

Thanks Again!

Anonymous said...

I have the same problems "driver install failure" with the CH341SER procedure. I use Windows 7 Ultimate (x64) build 7600. Next to that I tried the standard Prolific files. After using these program the driver is still not installed after I plugged in the cable. I don't understand what the exe file from Prolific is doing? Will the driver be installed on my system? If so, where can I find this?

The procedure as describes above is not functioning for me. Is there anything that can be done more to get it installed?

Thanks in advance!

Pim

Brian said...

Unfortunately, these drivers won't work with Windows 7 64-bit, as they are not signed. You can follow the instructions on the above comment as a workaround.

Just last week, I purchased an IOGEAR GUC232A USB-Serial adapter from B&H Photo for about $16 (including shipping). IOGEAR does have signed 64-bit drivers for Windows 7. To me, it was worth dropping $16 to find a device that has proper driver support.

Anonymous said...

Thanks for your comment!

As I mentioned already, your workaround is not working for my equipment (don't ask me why).

I'm living in the Netherlands (Europe). Do you have an internet adress where to buy this cable online? The link provide me with a shop whit a price of USD 29,95

kind regards Pim

Brian said...

A quick search on Google Product Search for IOGEAR GUC232A should give you a list of purchasing options. You could always try eBay as well.

Anonymous said...

thank you, I was so frustrating to trying to install it for at least 2hour, and i get here...it works now.
THANKS

Brian said...

Just an FYI...I got my IOGEAR GUC232 adapter yesterday, plugged it in and Windiws 7 64-bit installed the drivers automatically! I would highly recommend purchasing the IOGEAR adapter for anyone who can't get the Prolific adapter to work in Windows 7 64-bit.

Anonymous said...

@Brian
A scan of your CH341SER.EXE file with http://www.virustotal.com shows it's a worm.
Please, add a warning to your post !!!!

Brian said...

Thanks for the update, Anonymous! I apologize for unknowingly posting a link to a file that contains possible malware, and I feel terrible. I have reached out to MX-MART and until I can solve this problem, I have removed the link. I highly recommend that folks purchase the IOGEAR GUC232 as it works flawlessly with Windows 7 x86 and x64.

Brian said...

MX-MART responded with the following:

hi, did you get the che41ser.exe from the CD or our website link: www.mxmart.com/info/driver.htm

not sure how accurate is the virustotal.com; but we're confident the drivers are safe, hundreds and thousands have been sold and it's directly from the manufacturer.

It will be stupid for the manufacturer. But if you prefer, you can return it for refund. thks

CK said...

It's very probably a false positive. As you can see all the major AVs do not report a problem. Consequently you should post the driver ;)

Brian said...

If people think that it would be helpful, I can re-activate the link to the driver.

Marcos said...

Brian Your a bloody Legend!! it worked for me..
i finally got my HL-721 plotter to work under Windows 7 64Bit!!!
Took me days!.. But thanks for posting
about the " Driver Signature Enforcement Overrider tool "
it worked!!!

Anonymous said...

prolifics drivers worked for me when i set the compatibilty options of the driver setup program to vista.

Anonymous said...

Thanks VERY MUCH!! Been trying to find Windows 7 driver for this adapter for a while with no success. Again, THANK YOY!

Anonymous said...

Hey guys
You can find a better updated driver here http://www.winchiphead.com/download/CH341/CH341SER.ZIP It even works for x64 systems.

Anonymous said...

the driver you are posting is not a prolific driver as you suggested in your original post. From everything that I can tell, the IOGear adapter uses the prolific chipset actually...

Anonymous said...

The CH341 does not use a Prolific chipset, rather it has one of the clone chips, in other words counterfit chip. The new Prolific drivers have been modified so they won't work with the cheap counterfit chipsets. The Prolific drivers will only work with a true Prolific chip. It's been a pain in the butt, but you can't blame Prolific for trying to protect their products.

The ATEN device (GUC-232A) uses a true Prolific chip, but a different address, so the Prolific drivers won't work with the ATEN device either.

I've been waiting for someone to write a program that will find what devices are loaded on the PC and install the correct driver files. How hard could that be?

Right now, it appears that Serial devices are here to stay. Its' time to start putting a serial port back on these newer computers. Installing a USB to Serial Port Adapter is now the biggest challenged for the PC user today. Isn't that a ridiculous state of affairs?

JC said...

I can't thank you enough for this information. I finally got my Prolific cable working after trying drivers from the cable vendor, Prolific, & another generic set, neither of which worked. Thanks!!

Brian said...

@JC, glad you got it working! :-)

Vishal............Raut said...

where is the link of driver ?

Vishal............Raut said...

hi i am using windows 7 . 64 bit getting the same error, does that will help,, where is the driver link?

Brian Hall said...

Vishal, the link is available in the post above...look closer.

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