Web Service error - HTTP Error 500.19 - Internal Server Error 0x80070021

I created a simple web service in VS 2010 (target framework 3.5) and published in IIS 7.5 But when I tried to browse it got following error.

**HTTP Error 500.19 - Internal Server Error
The requested page cannot be accessed because the related configuration data for the page is invalid.
Error Code  0x80070021
Config Source:
97:     </modules>
98:     <handlers>
99:       <remove name="WebServiceHandlerFactory-Integrated"/>**

How to resolve this error?

It is working when Target framework is changed to 2.0/3.0 but not working for 3.5

One more thing I had installed VS 2010 before installing IIS. So is there will be any issues because of this?