Pasted from http://www.codetoday.net/default.aspx?g=posts&t=1595. Thanks to AdmOd.

1) In your IIS, identify your web site’s application pool as illustrated as below.

2) Go to Application Pools under your IIS

3) Right-click the early identified Application Pool, select “Advanced Settings” to go to the menu as shown below. Change the “Build-in account” value to “LocalSystem”