Watch out for this one, its possible whilst installing IIS on Server 2008 its easy to forget that you’ll need the Management Compatibilty Components – goodness knows why I kept forgetting it!
2. In the navigation pane, expand Roles, right-click Web Server (IIS), and then click Add Role Services.
3. In the Select Role Services pane, scroll down to IIS 6 Management Compatibility.
4. Click to select the IIS 6 Metabase Compatibility and IIS 6 Management Console check boxes.
5. In the Select Role Services pane, click Next, and then click Install at the Confirm Installations Selections pane.
6. Click Close to exit the Add Role Services wizard.
2. Open Internet Information Services.
3. Open Web Management Tools.
4. Open IIS 6.0 Management Compatibility.
5. Select the check boxes for IIS 6 Metabase and IIS 6 configuration compatibility and IIS 6 Management Console.
6. Click OK.
Also, a good link to visit when installing SharePoint 2010 and not too clear on what roles and features are required is here: http://sharepointnomad.wordpress.com/2010/07/23/installing-sharepoint-2010-on-windows-server-2008-r2-which-server-roles-and-features-do-i-need/
Installing SharePoint in various forms, Single, Farm etc
But, a really good place to ensure you have all the pre-requisities for installation is Technet – here: