IIS7 is a little easier, for those of you who are familiar already it won't suprise you that it's just another line in the good old web.config...
<location path="index2.html">
<system.webServer>
<httpRedirect enabled="true" destination="Default.aspx" exactDestination="true" childOnly="true" httpResponseStatus="Permanent" />
</system.webServer>
</location>
If you place the above snippet inside the