New windows 10 install and wrong extension file

Hi, you've not said what program created the rtb file type.
If we knew that, it might be possible to check the program is Win 10 compatible- does the site/author/help claim it is?

Basic question- does your program work correctly irrespective of the icon displayed for .rtb file types?

Perhaps you need to associate your rtb extension with that program:
Here's an example:
RTB File Extension - What is it? How to open an RTB file?

Tutorials available on associating file types in -yes- the Tutorials section here if needed.

It could also help if you choose to show file extensions in file explorer:

is a blue folder but it should be a .RTB extension.

I think perhaps you mean.. the icon for .rtb files isn't correct.
I.e. it does have a .rtb extension, but it should have a different icon.

Here's an example of how to view the way an icon is associated with a fle type, using Nirsoft's Filetypesman:

What is associated with your .rtb association?
(e.g. rt click, Properties).
Compare that with what is shown under Win 7.

Have you tried associating it manually?

I don’t think it does work as i tried to install that database through the program and gave me an error.

Try researching the exact error message, then post on a forum for that program, or its support.