As an additional information, I would like to share this experience.
After uninstalling .Net 4.8 and installing .NET 4.5.2, one of my existing software complained and wanted ,NET 4.6.2.
I had no other go. I had to install .NET 4.6.2.
Then with bated breath, I opened B4A.
Phew! It worked.
Now, I can officially confirm, win 7 and .NET 4.6.2 also works.