Allowing the host OS to shut off the power to the USB ports will cause U170 devices to randomly disconnect with a loss of the session and possible lost customer data.

Summary

Please make sure that your standard OS power settings do not allow the power to be shutdown to the U170 devices or the host to go to sleep while there are U170 users logged-on. There is one lesser known power management feature in the "USB Root Hub Properties" control window that could lead to this issue (host PC shuts down power just to the USB ports). The details of this setting are in the attached for Windows XP and Windows 7.

Note: This is one reason NComputing does not recommend notebooks as host PC's for the U170 as there are many power saving settings in a notebook that can cause this undesirable power behavior.