To configure elmah on iis7, read this post first:
http://code.google.com/p/elmah/wiki/DotNetSlackersArticle
If setting does not work… copy and paste these lines in right place
<system.web>
<httpHandlers>
<add verb="POST,GET,HEAD" path="elmah.axd" type="Elmah.ErrorLogPageFactory, Elmah" />
</httpHandlers>
<httpModules>
<add name="ErrorLog" type="Elmah.ErrorLogModule, Elmah"/>
<add name="ErrorMail" type="Elmah.ErrorMailModule, Elmah" />
<add name="ErrorFilter" type="Elmah.ErrorFilterModule, Elmah" />
</httpModules>
</system.web>
<system.webServer>
<modules runAllManagedModulesForAllRequests="true">
<add name="ErrorLog" type="Elmah.ErrorLogModule, Elmah"/>
<add name="ErrorMail" type="Elmah.ErrorMailModule, Elmah" />
<add name="ErrorFilter" type="Elmah.ErrorFilterModule, Elmah" />
</modules>
<handlers>
<add name="Elmah" verb="POST,GET,HEAD" path="elmah.axd" type="Elmah.ErrorLogPageFactory, Elmah" />
</handlers>
<system.webServer>
