Web service hosting in IIS : Error HTTP Error 500.19

Question

 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?