It took me a long time to take this on this issue once again and it required from me a lot of working hours spent on joggling with different disks / setups, but here is what I have finally established:
1] The font that holds all those signs is Marlett, visible on the drive as marlett.ttf. Once I copy that file to
C:\Windows\Fonts
the problem goes away after the reset
2] Microsoft did not make it easy for me to pin point the culprit [as apparently they really like to treat customers like idiots - Support of the WEBM video file format], because under the
Properties > Details > File description
I have zero information what it contains or what it is needed for. Many others fonts, also those with Copyright by Microsoft, have very informative data in that field. [So this seems the most vital font - and yet it was "described" like something disposable]
3] What the User [who is the Administrator] sees in the
C:\Windows\Fonts
using a file manager like FreeCommander or Total Commander or a photo manager like XnViewMP is something different that what is visible for the very same User when the (Windows) Explorer of Microsoft is chosen for navigation
4] When using Explorer the User is able to easily remove fonts from the Fonts folder of the active operating system for good
5] When using Explorer the User is unable to copy the fonts from the Fonts folder that is currently used by the operating system. Software like FreeCommander must be used
6] Using
Start > Settings > Personalization > Fonts
for managing fonts is a waste of time, to put it mildly. Some fonts cannot be removed at all, some other re-appear just after the supposedly performed uninstallation of them
7] In the Fonts folder I have encountered files in formats
- CompositeFont
- dat [just 1:
StaticCache] - fon
- ini [just 1:
desktop] - OTF
- ttc
- ttf
- xml [just 1:
fms_metadata]
After my initials trials, in the second run now I have left only the StaticCache.dat file [to be precise: I copied it from that other machine / system which was running A-OK with a minimal amount of fonts installed from scratch on it]; plus the INI file [which is responsible most likely for the icon of the Fonts folder]. Also I have no other fonts than those in format OTF, TTC and TTF
All in all: some fonts can only be removed by using Explorer - and Marlett is a must have in Windows 10 if you do not want to see graphical errors all over it
I will continue to work with the current setup for some time [I will simply use it on a daily basis for different tasks]. So far I have checked multiple programs, big and small, free and payable- all seem to have all those special graphic signs in them and all seem to a shortened list of fonts. I performed multiple resets of the system- but I did not yet updated my Windows so I do not know if my clean up will not be somehow reverted when I perform one [my updates are paused for good with a third party software and I try to manage requests of internet connections with COMODO Firewall as well as the internal requests for access by one process to another]
Later on I will restore my main system, implement the aforementioned changes [thus test them once again] and try to further lean up my list of fonts [thus confirm my findings] and also update it. And at the end of that process I will come back here report if my clean up of fonts is stable and not causing problems
And If everything will be working, I will then mark this post as the one containing the solution