Answer by subash adhikari for Cannot read configuration file due to insufficient permissions

1. Go to IIS, (sites)
2. Right click on project inside the sites.enter image descriptionhere

and click on edit permission.

3. Go to security.

4. click on edit button.

5. click add button. type COMPUTER_NAME\IIS_USERS

   or

6. click advance.

7. click find now button.

   and there is option to choose.choose IIS_USERS and click ok...ok....ok.