COM Security Requirements for Session Integrator
When using Session Integrator in an environment where the Client application and the Service component are running under two different user accounts, special configuration of COM security should be performed.
To configure COM security in Component Services
Click Start, then click Run, then type
DCOMCNFG, and then click OK.In Component Services, expand Component Services, expand Computers, right-click My Computer, and then click Properties.
In My Computer Properties, in the COM Security tab, under Access Permissions, click Edit Default.
In Access Permission dialog box, click Add to add the Server user context. If the Server is not on the same computer as the client, you must allow Remote Access to the user.
Click OK twice.