Hello,
just installed Seotoaster on a Windows Server 2008 with IIS 7,5.
Here the translation of .htaccess to web.config:
<rewrite>
  <!--Diese Regel wurde nicht konvertiert, da sie von IIS nicht unterstützt wird: RewriteBase /.-->
  <rules>
    <rule name="Importierte Regel 1">
      <match url="^\.htaccess$" ignoreCase="false" />
      <action type="CustomResponse" statusCode="403" statusReason="Forbidden" statusDescription="Forbidden" />
    </rule>
    <rule name="Importierte Regel 2" stopProcessing="true">
      <match url="^(.*)$" ignoreCase="false" />
      <conditions>
        <!--#canonicalization do not remove!-->
        <add input="{HTTP_HOST}" pattern="^www\.DOMAIN\.TLD$" ignoreCase="false" negate="true" />
      </conditions>
      <action type="Redirect" redirectType="Permanent" url="
http://www.DOMAIN.TLD/" />
    </rule>
    <!--#end canonicalization-->
    <rule name="Importierte Regel 3" stopProcessing="true">
      <match url="^index\.html$" ignoreCase="false" />
      <action type="Redirect" redirectType="Permanent" url="
http://www.DOMAIN.TLD/" />
    </rule>
    <!--#301 redirect-->
    <rule name="Importierte Regel 4" stopProcessing="true">
      <match url="^automated-301-redirects-seo\.html$" ignoreCase="false" />
      <action type="Redirect" redirectType="Permanent" url="
http://www.DOMAIN.TLD/More-information.html" />
    </rule>
    <rule name="Importierte Regel 5" stopProcessing="true">
      <match url="^(.*)$" ignoreCase="false" />
      <conditions>
        <!--#end 301-->
        <add input="{SCRIPT_FILENAME}" matchType="IsFile" ignoreCase="false" negate="true" />
        <add input="{SCRIPT_FILENAME}" matchType="IsDirectory" ignoreCase="false" negate="true" />
      </conditions>
      <action type="Rewrite" url="index.php" />
    </rule>
  </rules>
</rewrite>
(Change DOMAIN.TLD to your domain)
Greetings,
Michael