There is a known compatibility issue with current Line 6 drivers and the AMD USB Filter driver that comes preinstalled on several AMD computers including HP and Compaq. This issue materializes in the form of constant blue screens when connecting a Line 6 device via USB to these computers. Uninstalling this USB Filter driver will resolve this issue. Below is a link to an article that takes you through the uninstall process for this driver step by step.
Note: If you have an AMD PC with a different brand of video card or do not have ATI Catalyst installed and are still experiencing blue screens when you connect a Line 6 device you can manually check for the driver in your Windows system directory. If the driver is installed, it can usually be found at this location:
Delete the driver, restart your system and see if the problem still occurs when you connect your Line 6 Hardware.