SQL changed sa password

SQL Server Administration
1

Hi there.
Today I changed 'sa' password to my SQL Server.
It works fine, but I cannot acces the DB from any of the applications. When I try to login from the application window, it says: ,,Login failed for user sa,,.
I don't know how to solve this problem. I think I'll have to replace the old password with a new one also in some kind of connection code-lines, but I don't know how or from where. I don't know the older password.
I'm sorry for my bad English. For any questions, please aks.

I hope you can help me,
Best wishes.

2

Your English is superb but ...what is this application you talk about and why are you using sa as the user for the application

3

Thanks!
I work at a city hall and through this application we give registration numbers to documents.
I'm new on this field and I have not been trained about the city hall's Server; the other programmer isn't working anymore.
I wanted to export the database from the server, but some tables were encrypted. I know it may sound stupid, but I thought that changing the 'sa' password would solve the Error and wouldn't do any damage. So, unfortunately, I don't know why the apps are using sa as a user, but I know they do due to the Error.
Thank you for your time & answer.

4

what is this application you talk about . web app, access app?

5

It's an access app. It uses something like 'admin' - 'admin' username and password, and apparently, it connects to the server..