Getting error The Workstation service has not been started. We regret for the inconvenience caused. Object reference not set to an instance of an object.

Hi All,
I get the following error/exception in my IIS configured ASP.NET web applcation:
The Workstation service has not been started. We regret for the inconvenience caused. Object reference not set to an instance of an object.
It was working fine till yesterday in IIS 6.0. Now its working fine in VS 2005 IDE.
Integrated windows authentication is enabled.
Please help me, its getting critical.
...