...I only want to find a solution for restoring to January 2019, just before that last MS update...
If Dr. Jonas Moses still has a restore point from January 2019, he should boost the amount of drive space that system restore is permitted to use to avoid having it vanish ... the PowerPoint problem may return and the restore point may be needed again.
Old restore points are deleted to stay within the permitted drive space allocation.
AFTER increasing the drive space allocation, the good Dr. really should follow the step-by-step instructions that use "system configuration" to reboot into "safe" mode and find the command prompt right click to run as administrator and type rstrui to
start system restore. Safe mode doesn't start the crowd of processes that start in normal mode, so system restore is less likely to trip over something and fall flat on its face.
In re: the PowerPoint problem that precipitated this saga ... searching "powerpoint crashes inserting image" turns up solutions for many different issues rather than one solution repackaged as click-bait for many different sites. Of the Microsoft articles
describing one from November 2018, one seemed more timely, it suggests that an Intel graphics driver has to be updated, i.e. a Powerpoint update uses the graphics driver differently and ran into a bug and chose not to work around it. There's no shortage of
possible underlying causes, like software conflicts and running out of memory. A number involve a security update interfering with inserting some type of images or media someone that someone figured out how to hack. The gremlins have more than a year's head
start now, so you may have to jump through several hoops to disable the "protection" added by updates before image insertion works.
If the system and software aren't recent and your time is valuable, e.g. minimum wage, then taking advantage of a new PC's warranty to make someone else solve the problem is more cost effective than chasing bugs yourself. If Powerpoint doesn't insert images
correctly and they can't fix it within 2 days, return it and buy a different one. Don't wait on hold for support or some mythical senior pubah. A computer is a tool invented over 70 years ago. Treat it like one. It either works or its out.