Report Builder Help

I have been doing everything in Report Designer....now I just tried report Builder after using a Model I creted to create a report. When I try to run the report, it's prompting me for a username and password. Where and how can I switch this to Windows Authentification? The dataset it's supposedly using already has windows authentification as the method. But the strange thing is, when I click on View Report, it gives me another dataset name called dataset1 saying that I must first supply a username and password...where did this generic dataset name come from? What dataset is this refering to ? it certainly isn't the one I uploaded from my Model Project.

Even when I procede to input a generic username and password, then I get "The type of the data source has not been specified."

I don't want any of this, I just want the windows authentification to do it's job based on what users I have allowed permissions in Report manager to whatever needs to be set!

Your report model should be bound to a data source. That data source usually needs to use stored credentials if it connects to a separate machine, because the credentials provided by the client are only valid for one hop (i.e. from the client to the report server). Is that the problem?|||you are correct, thanks!!|||So how'd ya fix it
|||I'm getting the same error message. The credentials are being stored but the reports still won't run? Help..I'm on the clock.

The type of the data source has not been specified.
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An error has occurred during report processing.