If you are using XP and have installation issues. Specifically the CDC Drivers found at “USB Debugging with Virtual COM Channel” on this page
Make sure you are on Service Pack 3 and that the file usbser.sys in the windows\system32\drive folder.
- related link
I found this file in the windows\driver cache\i386\sp3.cab (but was already installed) just in case someone looking for it and not found in the same place as described in the above post.
Note: I added this post because I had some additional details but also didn’t find the other post until I had tracked down the issue and searched for usbser.sys. So using the terms installation issues, failed, CDC Drivers, Virtual and XP in the same post will help it will show up in the search easier for others.