I'm sorry to hear that and don't know why it should have happened.
I suggest you use the program's Registry Backup to restore the registry, but if that doesn't resolve, then go into System Protection and use your restore points.
I've always created a system image prior to test running new versions of the repair program and Shane advises manually creating a restore point before using the program.
Ignore the program's option to create a restore point because while it says it has done so, it doesn't physically create one.
To restore your Windows to how it should be, I would suggest performing a repair install for which you will need install media.
You can create install media after reading -
https://support.microsoft.com/en-us/windows/create-an-iso-file-for-windows-10-38547366-1dcb-7afd-1726-9eb222d72705Once you've created the media (DVD or USB) open Windows/File Explorer - This PC - insert the media and double click on its drive.
This will start the process when using a DVD but will open to its files when using an USB where you would then double click on set up Application.
A repair install doesn't affect installed programs.