It should have been a new topic but it can stay where it is.
That's quite an old version of Win 10 you have.
Sometimes machines won't be updated by Microsoft because the hardware isn't compatible.
The current version of Win 10 is 1909 18363.592
You could try a manual check for updates or use the MCT to see if the machine will update, but create a system image and the means to recover with it before using the MCT.
https://www.microsoft.com/en-gb/software-download/windows10Use the update option.
Did AVG start playing up after you installed Photoshop7 ?
To see if either is conflicting, I would uninstall both AVG and Photoshop then reinstall just AVG to see how it performs and then install Photoshop if AVG performs as it should.
However, prior to doing that, you could open Event Viewer to see if it has recorded anything for either AVG or Photoshop.
I wouldn't go playing around with the registry but you could open a Command Prompt (Admin) and enter these cmds to see if there's any difference prior to uninstalling those programs.
dism /online /cleanup-image /startcomponentcleanup
dism /online /cleanup-image /restorehealth
sfc /scannow
exit
The first two should report completed successfully and the sfc /scannow should report that it has repaired all corruption or that there is no integrity violations.
Let me know if they report different.