Thanks, your steps did the job.

So it means every folder needs the MSSQL$  user if the database want to be able to connect...hmm.

I have another folder...

I did not deleted the users  in users/group, as I understood only to delete the user I made, I only deleted the long ID n umber in thr permission folder,...

Will give it a try, and I don't remember anymore what I selected during install of SQL epress, 

in user/groups there is an account made by SQL that...

Dear 

thanks, indeed, software was not working because of another issue.  after again some hours, finally the connection to the SQL works .

Hope to optimize it and...