USB drivers for the SCS Pactor modems

Any USB device requires drivers to operate. In some cases (keyboards, mice) these are included with Windows, but in most cases they are provided by the device manufacturer (SCS, in the case of the USB-connected Pactor modems).

This note applies to the SCS USB-connected modems: the PTC-IIusb, DR-7800 Dragon, and the PTC-IIIusb, and “PTC-IIusb” here will refer to any of these modems. Serial-connected modems (PTC-II, PTC-IIe or IIex, PTC-IIpro) may be connected with a USB/serial adaptor, those also require drivers and much of this note will apply– except that the driver-files must come from the manufacturer of the USB/serial adaptor, and not with Airmail nor from SCS.

For the SCS PTC-IIusb and other USB modems, the drivers are provided on a CD-Rom that was provided with the modem, or can be downloaded from the SCS website, and are also installed with Airmail. Once installed properly, the drivers will create a virtual “COM port” to access the modem.

There are some potential wrinkles: Drivers on a CD that came with a modem that was purchased years ago will not be compatible with newer versions of Windows. Similarly, an older version of Airmail may not have installed the newer drivers needed for Win-7, and in particular Win-7 64-bit version. Also, if the modem was plugged in before the drivers were made available then Windows may have “given up” trying to install it, even after the drivers are available.

This note will outline how to check for USB driver issues and how to fix them. You need to be logged into the computer as an “administrator”, usually the primary (first) login if there is more than one. For Win-7 you can check (and change) your user-status in Control Panel, “User Accounts” (select “small-icon” view in the upper-right part of the Control Panel window).

If the drivers are installed correctly then Airmail’s “Setup Wizard” (Tools menu) will automatically find the PTC-IIusb modem, and show the correct COM-port on the “HF-Modem” page.
If it doesn’t, then cancel that window and proceed with some checks:

Device Manager:

First, open Windows “Device Manager”. Start by opening Windows Control Panel, select small-icon view (upper-right) if needed, then find “Device Manager” and click on that. This opens the Device Manager window, which shows all connected hardware devices.

Start by looking for yellow “?” or “!” icons (symbols), those are “unknown devices” and indicate that something is not working– perhaps the modem, maybe something else. A modem with no drivers may be listed as “USB serial port” with a yellow icon, that is the same thing as “unknown device”. Leave the Device-Manager window open and disconnect the modem’s USB cable from the computer. Does the yellow icon disappear? If so then the “unknown device” is your modem, continue below.

If there are no yellow icons, then find “Ports” and expand that by clicking the little arrow. The “SCS PTC-IIusb” should be listed there, along with the assigned COM-number. Note that COM-port number, then compare to Airmail’s settings (Tools menu, Options window, connection tab) and correct that setting if needed. The baud rate for a PTC-IIusb modem is always 115200.

If you do find an “unknown device” (yellow icon) and you have confirmed that it is the modem (by disconnecting and reconnecting the USB cable), then we need to sort out drivers as follows.

Installing Drivers:

The Airmail install program also installs the SCS drivers, but older Airmail versions will not have the correct drivers for newer versions of Windows. Specifically, Airmail ver 3.4.062 has drivers for all Windows versions including Win-7/x64 (64-bit), while Airmail ver 3.4.034 is only good through Win-7/x86 (not 64-bit).

So if you have an older version of Airmail, then download the latest Airmail version (3.4.062) and install that, making sure that the “Install PTC-IIusb drivers” box is checked on the last page. Do this with the modem unplugged from the computer. Then power on the modem and plug in the USB cable, Windows should automatically find the drivers and install them. Restart Airmail and run Airmail’s setup wizard.

If you have deleted driver software (below), then you can always re-run the Airmail installer program. If you don’t change any settings, then the installer will not change your Airmail setup. When you get to the last page, check the box that says “Install PTC-IIusb drivers” and click “Finish”. Do this with the modem unplugged, then reconnect the modem and power it on.

If Windows can’t find drivers, or Airmail still can’t find the modem, then be sure the modem is connected and powered on, go back to Windows Device Manager and find the unknown device, right-click on that icon (i.e. click with the right mouse-button, not the left), and select “Update Driver Software”. Select “Search Automatically”, and wait while it searches for drivers. If Windows reports success then proceed as above with Airmail’s setup wizard.

Downloading drivers:

If still no luck then download the drivers from the SCS website. Go to and click on “Download” at the top, then scroll down that page and click on the link for USB drivers:
“USB driver for SCS PTC-IIusb …”. On the next page click on the driver file which will be “SCS USB Driver 2.08.02 WHQL” or similar, and save that file to a “downloads” folder.

Now open your “downloads” folder (whatever it is called), and open the file that you just downloaded. It will be a compressed “zip” folder, containing another folder called “SCS USB Driver 2.08.02 WHQL Certified” or similar. Copy that folder to a “Drivers” folder on the local hard drive (C-Drive) where it can be easily found– create a new “Drivers” folder if it is not already there. So under “Local Disk” you have a “Drivers” folder, and under that the “SCS USB Driver…” folder.

Installing drivers manually:

Once drivers are downloaded and saved in a “Drivers” folder, go back to Device Manager and find the “unknown device” again, and again right-click and select “Update Driver Software”. This time select “Browse my computer”. Click the “Browse” button and select the “SCS USB Driver…” folder that you downloaded and and copied to the “Drivers” folder. Click “Next” and wait while Windows installs the drivers.

Windows may come back and report success, in which case you should be done– go back to Airmail’s setup wizard, above, and see if Airmail finds the modem. If Windows says that the drivers could not be installed then unplug the USB cable, wait a few seconds, and reconnect. Check Device Manager– the modem should be listed as “SCS PTC-IIusb” under “Ports”. Continue as above.

Deleting old drivers:

If still no luck, and you have either downloaded the drivers from the SCS website, or you have the current Airmail install program, then the next step is to delete any current PTC-IIusb drivers and start over. Go back to Windows Device Manager, find the PTC-IIusb or “unknown device” icon, right-click on that and select “Uninstall”, and check the box that says “Delete driver software” (if visible). Click OK, Windows will uninstall the device and delete the current drivers.

It should re-appear as an unknown device, if not then select “Scan for hardware changes” (Action menu) or disconnect and reconnect the USB cable. It should now be an “unknown device” (yellow icon). If you don’t see it then check under “Ports” for a “SCS PTC-IIusb modem”, it might be re-installed but with older drivers– repeat the “Uninstall” (and delete driver-software) as many times as needed until it appears as an “unknown device” or (“USB Serial port” with a yellow icon). Then proceed with “Installing drivers”, above.

If there is still no luck then something is likely broken. Try a different USB connector on the computer, try your modem on a different computer, or try a different modem on your computer– the USB interface may be faulty.

(revised 2012-05-05)