Web: How to get the exact error on an IIS site

You will get the above error on windows 2008 even if you have set CustomErrors=Off in the web.config file .
To get the actual error on the remote machine or remote browsers
Double click on the website in IIS 7.x.
Double click asp.
Double click debugging properties option and set send Errors to browser equal to True and click apply.
Double click on the website.
Double click error pages.
Click Edit feature settings.
Check the radio button “Detailed Errors” and click ok.