I would suggest that you use the Line 6 Uninstaller located at the location below to remove your currently installed Line 6 drivers:

Windows 7/Vista  -  C:\Program Files(x86)\Line6\Tools -  Line6Uninstaller

Make sure to disconnect any of your Line 6 USB devices prior to starting the uninstaller. Make sure to only check the boxes at the bottom of the list that are related to the Line 6 drivers, and proceed to uninstall them. Once they are removed, restart the computer. Upon restart download the latest Line 6 Window Drivers from the link below:

Windows Drivers 4.2.5.4:

http://line6.com/software/readeula.html?rid=4791

Make sure not to connect your Line 6 USB device until prompted to so at the end of the installation process. After connecting it, make sure and look towards the Windows system clock for a notification that Windows has detected your device and has successfully installed the drivers before moving forward. If you do not receive this notification message, make sure to try reconnecting the Line 6 hardware to each available USB port until you have exhausted all available USB ports.

Once Windows has detected your device, close all open applications and launch the Line 6 License Manager application. Log into your Line 6 user account, next select your computer on the left hand of the program, de-authorize it and re-authorize it. Next select your Line 6 USB device from the left hand side of program and de-authorize it, you should be given the option to "REMOVE" your licenses from the device, proceed to do so. After that finishes, re-authorize your device and you will be given the option to "INSTALL", proceed to install your software licenses back into your hardware.

If you still have questions, please know that Line 6 is no longer supplying support via the forums. Instead, you can create a direct support ticket at:

http://line6.com/support/