Using ArcObjects in standard web service

Dear All,

I created a standard web service using C# VS 2010. The operating system is Windows 7 and IIS version is 7. I added ArcGIS references to the C# web service project and tried to do: IAoInitialize m_pAoInit = new AoInitialize(). It can be done. But when I tried: IPoint p = new PointClass();

Then I got the following error:
Retrieving the COM class factory for component with CLSID {00A5CB41-52DA-11D0-A8F2-00608C85EDE5} failed due to the following error: 80040111 ClassFactory cannot supply requested class (Exception from HRESULT: 0x80040111 (CLASS_E_CLASSNOTAVAILABLE)).

Any suggestion? Thanks in advance!