Unable to install Prolific USB-to-Serial Comm Port driver - Windows Vista and Windows 7

Published: 2008-12-05

 

Last Updated: 2010-07-26

Applies To

Symptoms

When connecting the TKS USB-to-Serial adapter cable to a Windows Vista or Windows 7 PC, the Found New Hardware wizard launches, searches for the driver, then prompts the user for a CD or path to the driver.   In Device Manager, the cable shows as Other Device - USB Serial Controller or Other Device - Prolific USB-to-Serial Bridge.

 

Cause

 

Resolution

  1. Close all open programs.
  2. Click Start, then click in the search box.
  3. Type devmgmt.msc then press Enter. Click Continue at the UAC prompt if it appears.
  4. In Device Manager, right-click the "Other Device" entry for the USB cable and select Uninstall.
  5. Click Yes or OK to confirm the uninstallation.
  6. Disconnect the USB cable from the PC.
  7. Restart the PC (required).
  8. Find the driver installer.
    • If you have Guard1 Plus version 2.80 or newer, the Prolific driver installer can be found in the Drivers folder on your Guard1 Plus CD.
    • If you have Guard1 Plus SE version 4.40 or newer, the Prolific driver installer can be found in the shared folder Guard1 Plus SE Server\Attendant SE\USB and Direct Downloader Drivers.
    • If you have a version older than 2.80 or 4.40, or you cannot locate your CD, download the driver installer for Windows Vista/7. Save the file to a folder on the Guard1 Plus PC.
  9. Double-click the driver setup file. Follow the prompts to install the driver.
  10. When the installation is complete, connect the USB cable to the PC.
  11. Windows should detect the cable and install the driver automatically (indicated by balloon messages from the System Tray).
  12. Repeat Steps 2 and 3 to open Device Manager.
  13. Expand the folder Ports (COM & LPT).
  14. Confirm that there is an entry for Prolific USB-to-Serial Comm Port COM#.
  15. Your cable is now ready for use. NOTE: if the COM# shown in Step 14 is higher than 8, refer to How to check or modify COM port settings.

 

You may be prompted for the driver for the TKS Direct Downloader - if so, choose Do not show this message again then click Cancel. There is currently no 64-bit driver available for the TKS Direct Downloader. However, the Downloader does not require a driver and will function normally.

 

 

After Step 10 above, you may receive the following error:

 

 

Additionally, the Device Manager > Ports (COM & LPT) folder may have an entry for Prolific USB-to-Serial Comm Port with a warning icon (!).

 

If you encounter this error, the Windows Registry entries for the hardware have not been updated successfully. Resolving this problem requires searching and editing the Windows Registry.

 

Important: This article contains information about modifying the Windows Registry. Before you modify the Registry, make sure to back it up and make sure that you understand how to restore the Registry if a problem occurs. For information about how to back up, restore, and edit the Registry, click the following article number to view the article in the Microsoft Knowledge Base:

 

KB256986 (http://support.microsoft.com/kb/256986/) Description of the Microsoft Windows Registry

 

You must be an Administrator to edit the Windows Registry. If you do not have Administrator privileges, or are not familiar with the terms and methods described in the procedure below, please contact your IT Department for assistance.

 

  1. Close all open programs.
  2. Click Start, then click in the search box.
  3. Type devmgmt.msc then press Enter. Click Continue at the UAC prompt if it appears.
  4. In Device Manager, expand the Ports (COM & LPT) folder.
  5. Right-click the "! Prolific USB-to-Serial Comm Port" entry and select Uninstall.
  6. Click Yes or OK to confirm the uninstallation.
  7. Disconnect the USB cable from the PC.
  8. Close Device Manager.
  9. Click Start, then click in the search box.
  10. Type regedit then press Enter.  Click Continue at the UAC prompt if it appears.
  11. In Registry Editor, click My Computer at the top of the folder list in the left window pane.
  12. Click Edit > Find (or press CTRL+F on your keyboard).
  13. In the Find What field, type Prolific.
  14. Verify that the three checkboxes under Look at are checked.
  15. Click Find Next.

 

Registry Editor will search for the first entry containing "Prolific". Once the entry is found, you must delete it by right-clicking the parent key and selecting Delete, then Yes. To find the next entry, press F3 on your keyboard.  Continue finding and deleting all keys containing "Prolific" until no more remain.

 

After all entries are deleted, restart the PC then perform Steps 1-15 under Resolution above.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Copyright © 2013 TimeKeeping Systems, Inc.