I found this problem when my colleague, when they have problem with their USB to Serial Converter. They use windows 8, and I use windows 7. event we have different OS version. I try to share my driver to them. I use Prolific USB to Serial Comm Port Version It's easy to Install..

Steep to Install

  1. 1. Download The Software then Extract
    Link Download
    After download, unzip then run the installer.
  2.  Open devce manager with:
    - Go to windows then right click on  computer tab,
    - After that, choice device
  3. When device manager was opened, Open Profilic dialog box:
    - Click device manager
    - Go to Ports (COM & LPT)
    - Right click Prolific USB-to-Serial Comm Port
    - Click Update driver Software
  4. Update driver Software appear, then click "Browse my computer for driver software"

  5. After click the choice, another window appear, you should choice "Let me pick from a list of device drivers on my computer", then click Next

  6. After that, choice the valid Hardware driver, if you have a lot of  hardware driver make sure you choice, then click Next

  7. After install, a window with text "Windows has successfully updated your driver software" you may close the window then.

  8. Verify your driver after update:
    - Right click on Prolific USB-to-Serial Controller Comm Port
    - Then click Properties

  9. Make sure driver is update:
    - Go to Driver Tab
    - Look at driver version

Hope this tutorial can solve your Problem :)