Thanks, j-v. The program is Movie Studio 16 (Build 158) and is running on my Lenovo desktop PC running Wondows10 Home edition. Pentium Dual 2.20GHz, 4GB RAM. No extras that I am aware of other than what the program installed. My previous version was Sony Vegas 9 and it ran much faster on Windows 7!
I feared as much, j-v. Such is the cost of progress. I was happy with version 9 and windows 7 - I only really use the program to make small music videos for posting on my YouTube channel.