This is the "windows media sharing system" scanning everything in your "my pictures" folder to see what can be shared with other computers on your network.
This is one of many reasons not to have your LR catalog(s) in the "my pictures" folder.
The easy fix is to move your catalog and its matching previews folder to a different location, maybe folder named "LR_catalogs" beside your "my pictures" folder.
Alternatively, there may be a way to turn off the media sharing system, if that is not something you use for you pictures and music.
Thank you. I had done some more research and come to a similar conclusion that the media sharing was behind it. As an interim measure I turned it off and problem of constant drive operation has decreased markedly. I am still seeing other services accessing these files. These services are associated with my virus protection software. I am checking further.
Thanks again for your assistance.
Solution to virus software problem continually accessing LR files lay in uninstalling and reinstalling the AV Software. LR performance and general performance of PC has improved dramatically. Thanks again to ManiacJoe for his helpful advice