I can\'t seem to get any ASP.NET sites to run under IIS8 on Windows 8. Under IIS Express they are fine, but I\'ve:
If you have a new machine / formatted your machine, while installing IIS, make sure that you ticked installing ASP.Net (appropriate version).
Hint : Turn Windows Feature ON/OFF --> IIS --> Application Development Features --> ASP.Net 3.5 / 4.6
Recently I have upgraded to Windows 10 (IIS 10) & as I had forgot to install ASP.Net, I was facing this issue.
Other troubleshooting tips are:
2) Make sure you have given read permission to IIS_IUSRS group on your application folder.
3) You may check if your Application Pool has correct target .Net framework selected.
4) Make sure your Web.config is proper (well defined XML) and has no errors. Thanks.