I'm working on moving an existing Umbraco 6.2.6 site from Windows Server 2003 to 2008 R2. The site loads almost correctly, one of my macros is failing. But, my biggest issue is I cannot get the back office to come up. I am getting "No http handler was found for request type 'GET'". The full error stack is below:

[HttpException (0x80004005): No http handler was found for request type 'GET']
   System.Web.HttpApplication.MapIntegratedHttpHandler(HttpContext context, String requestType, VirtualPath path, String pathTranslated, Boolean useAppConfig, Boolean convertNativeStaticFileModule) +899
   System.Web.HttpServerUtility.Execute(String path, TextWriter writer, Boolean preserveForm) +464

[HttpException (0x80004005): Error executing child request for umbraco.aspx.]
   System.Web.HttpServerUtility.Execute(String path, TextWriter writer, Boolean preserveForm) +795
   System.Web.HttpServerUtility.Transfer(String path, Boolean preserveForm) +57
   System.Web.HttpServerUtility.Transfer(String path) +29
   umbraco._Default.Page_Load(Object sender, EventArgs e) +61
   System.Web.Util.CalliEventHandlerDelegateProxy.Callback(Object sender, EventArgs e) +51
   System.Web.UI.Control.OnLoad(EventArgs e) +92
   System.Web.UI.Control.LoadRecursive() +54
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +772

I've compared settings, web.config, all I can think of with a known good site running Umbraco 6.2.6 as well on Windows 2012. Nothing stands out. Anyone have any ideas?