Website giving an error Retrieving the COM class factory for remote component with CLSID

I have got a website which was working fine until today and all of sudden I am getting following error message when tried to access the website.

Retrieving the COM class factory for remote component with CLSID {xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx} from machine MMMMMMMM failed due to the following error: 80070005.

There's has been no changes to the code base,no changes to its dependencies and nothing noticeable. So remember the word noticeable, simple to say but very hard to point out. The error code 80070005 usually means that you do not have enough permission.

That does not help at all why would I get an error message as not enough permission if I am using windows authentication for the website. After digging some more the situation is this website is making a call to another webservice which is giving this error message.

Fine now both of them are running under the same application pool then it should work, but its not. Finally working through all the odd methods I have found impersonation is set to true for the website that's hosting the web service. I have just made

impersonate=false 

and yes that started working.

All in all the point I have missed out in my investigation is checking web.config. Anyway lesson learned for next time.

Information technology and business are becoming inextricably interwoven. I don't think anybody can talk meaningfully about one without the talking about the other. ~Bill Gates