winforms authentication

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Hi there, I have to implement winforms authentication on my little
document management tool.
The must implement authentication 2 kinds:

1) simple user and pwd authentication with these information stored
into its databse
2) winforms authentication:
- local if the apllication will run in a stand-alone machine
- networl if the application will run on an Active Directory Domain

I need resource, patterns and best-practise that talk abput the second
scenario.

Can you please help me?
.