Solved by changing the problem:
First, finally found which Kaspersky feature was interfering with System Restore (Self Defense) temporarily disabled / unchecked it and System Restore worked. Interestingly the box checked itself again by itself after the Restore operation and was able to Defend itself without needing my assistance (am continually impressed with Kaspersky)
Gave up on the main and overriding initial problem of totally ineffective "delicate" non-functioning Spotlight and instead simply (and safely) downloaded free Dynamic Theme app. Have set "daily Bing image as dynamic tile of application" for Lockscreen
Works, and when it would provide a pic I dislike, have now several good, quick and easy options, including using for Lockscreen that day a specific Windows picture I happen to really like