Enabling the "Remember Login" checkbox on your DotNetNuke web site requires a web.config change.
If you want to make similar changes to your own site, edit your web.config and update the following nodes to whatever value you require (the approriate fields are identied in bold below - all values are in minutes i.e. 60 minutes*24 hours*14 days=20160).
<forms name=".DOTNETNUKE" protection="All" timeout="120" cookieless="UseCookies" />
<add key="PersistentCookieTimeout" value="20160" />
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