Error reading comm device windows 7

There's a free nagware trial too if you want to make sure it will work before you buy it. Last edited by jpbro; Apr 6th, at AM. Is it only with a virtual serial port that this problem exists I don't have any real hardware to test it on right now, so I'm using a virtual serial port driver instead?

Or does it not work on real hardware under Windows 10 either? I wonder if it has something to do with me installing Visual Basic 6 on Win 10?

I heard that Win10 actually has some of these files that come with the OS to support legacy software that had been compiled in VB6. I'm guessing that the version of MSCOMM that comes with Windows 10 is different than the version that comes with VB6, in order to support the different base operating system different than pre-Win10, like Win98 that was around when VB6 existed.

Last edited by Ben; Apr 7th, at PM. I've been using that now, to run some tests on the virtual serial port, and so far no problems. Search for mscomm You are right.

Because mscomm You can get a program "working" this way only to see it fail miserably in the real world. Only one is needed but I didn't want any dangling wires. Yellow and green are cross-connecting the transmit and receive pins. These adapters typically provide 5V or 3. In this case we don't want to connect the power pins. To use this lashup for loopback testing on one PC you might want to use a simple non-powered USB hub if you are running out of sockets.

Many people working with IoT and microcontrollers already have at least one of these devices. They are pretty common. Last edited by dilettante; Apr 7th, at PM. NET VB. Advertiser Disclosure: Some of the products that appear on this site are from companies from which TechnologyAdvice receives compensation. This compensation may impact how and where products appear on this site including, for example, the order in which they appear.

TechnologyAdvice does not include all companies or all types of products available in the marketplace. Remember Me? Advertiser Disclosure. Advanced Search. Available forum solutions to this problem are half-baked.

Even vendors selling their "USB to Serial" adapters are baffled. Main cause of this issue is because the device you own contains a counterfeit "Prolific" chip China clone. To solve this intellectual infringement - original Prolific company modified their newest drivers to render the counterfeit adapters unusable.

Unfortunately this decision also renders all earlier adapters inoperative. If your adapter was working prior to going to Windows Update, you can "roll back" to the previous installed driver and all will be well once again. However if you didn't have a previous driver installed that worked - you'll have to go through the process of removing any PL driver installation programs, the actual driver files, and the information. What worsens this issue is that there are many "Prolific Driver Removal Tools" that do not work properly.

And Windows 8, 8. So no matter how many times you remove the driver files and reboot - the next time you insert the USB-To-Serial adapter, Windows installs the newest non-working version again. If working correctly, the device driver looks to Windows just like any other serial port. Unfortunately, in your case, this isn't working. The only suggestion that I have is to try another modem. There is nothing that you can do at the application level to fix this Unless, the actual problem is cause by port sharing, and that the device driver is returning a bad error message the message that it should use in this case is "Port already Open", perhaps.

You can try disabling any potential conflicting software, such as Winfax or MS fax -- these TAPI applications open the port, waiting for a fax call.

Error - Error reading comm device. Crystal error: error ocurred reading records: error in compiling sql expression.