Background Tasks are not running

For the past 2+ weeks most background tasks are not running automatically (Silent Mode is OFF).

Earlier last week I re-installed NS and manually ran Live Update until there were no more updates to download/install. (Auto Live Update is ON).

Full scan was run manually after the re-install, but has not run automatically since (set to run every 7 days).

Quick Scan has run on ONE TIME automatically about 14 hours ago.

This is happening on a Win 7 Pro SP1 desktop (NS 22.7.1.32).  However a Win XP Pro SP3 desktop seems to be working fine (NS 22.7.1.32)

An suggestions would be greatly appreciated.