Hi,
follow those steps below
1) right click on the folder "WebSite" and click on the Property.
2) then click on the security tab and click on the add button
3) Type "aspnet" and click enter
4) you can see "ASP.NET Machine Account"
5) give it full access and click ok.
If till not working then change something in IIS
check ASP.net Vertion
Also set "Application Protection" to "Low (IIS Process)
(see images)
Thanks
Santanu