I am developing a website,where I am using windows authentication for my connection. I want to change that to server authentication. I want to know what are the steps needed, at what should I watch out, and is there any problems that will appear in my project due to this change in the connection type?
Thank you

In SQL Server Management Studio, connect to your server. Then right mouse click on the Server in on Object Explorer window and select Properties.
This should show a new dialog, and a 'Select a page' panel on the left - choose Security and the you should see the settings to change the Authentication mode.
As the option is SQL server and windows authentication - I can't see it affecting your existing work. Just be careful that things don't just work as it's you logged into windows!
Nige

Thanks for the help Nige. Its that I am using windows auth in the connection string in my website. I want to change it to server auth, but in my server its windows server auth mode.
I can login as windows auth, but i cann't as server auth. I don't know how to make that database that I am working on be logged on as server auth, and how to get the admin pass if it ever existed to change it.
I have no experience in server security, I need a help to setup the server auth.I mean how to login if I dunno what the password ad username for the first time and where to change it.

Thank you