Putting that error message into Google returns thousands of hits with the solution. There are also a list of identical questions on the right-hand side of this page.
- Log in to the server;
- Open Windows Explorer, and locate the folder where you have deployed your application;
- Right-click on the folder and select "Properties";
- Select the "Security" tab, and click "Edit...";
- Click "Add...";
- Enter "IIS_IUSRS" (without the quotes), and click "Check Names";
- Once the group name has resolved, click "OK" three times";
You should now be able to browse to your application.