In your web.config inside system.web add this:
<membership>
<providers>
<remove name="AspNetSqlMembershipProvider" />
<add connectionStringName="LocalSqlServer"
enablePasswordRetrieval="false"
enablePasswordReset="true" requiresQuestionAndAnswer="false"
applicationName="/" requiresUniqueEmail="false"
passwordFormat="Hashed"
maxInvalidPasswordAttempts="5" minRequiredPasswordLength="2"
minRequiredNonalphanumericCharacters="0"
passwordAttemptWindow="10"
passwordStrengthRegularExpression=""
name="AspNetSqlMembershipProvider"
type="System.Web.Security.SqlMembershipProvider, System.Web,
Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" />
</providers>
</membership>
Also, you may need to edit some details according to your database.
notice the options you have for your password strength. use it wisely!
Yossi.