from last so many times I am getting the below error.As I am using the Microsoft Word dlls to create word files which further attached to the mail.
Server Error
I found the solution,
using DCOMCNFG.exe open it and go to Component Service ->Computers->My Computer->DCOM Config-> check for Microsoft Office Word option and select tab Security.Here you will get the options for Launch and Activation Permission->select Customize and click on edit and the add the user that will runs your Application with full access.
That's all ,this resolve my problem hop this will help.