There have been a few circumstances where the settings for the Windows recording device attached to the line inputs on the rear of the IP100-series products get changed back to Windows default values, rendering it unusable by the GCK software. On circumstance recently discovered was the application of certain Microsoft Windows Security Update for Windows 7 Embedded (KB4516065), but there could be other situations where this occurs. The attached document explains in detail the required settings to be restored manually if necessary.