Impersonating User plugin code mscrm 2011

            #region Impersonate user

            IOrganizationService service = factory.CreateOrganizationService(context.UserId);

            Guid userId = new Guid();

            QueryExpression qep = new QueryExpression();

            qep.EntityName = "systemuser";

            qep.ColumnSet = new ColumnSet();

            qep.ColumnSet.Columns.Add("systemuserid");

            ConditionExpression conExp = new ConditionExpression();

            conExp.AttributeName = "fullname";

            conExp.Operator = ConditionOperator.Equal;

            conExp.Values.Add("SYSTEM");

            FilterExpression fep = new FilterExpression();

            fep.Conditions.Add(conExp);

            qep.Criteria.AddFilter(fep);

            EntityCollection enCol = service.RetrieveMultiple(qep);

            foreach (Entity team in enCol.Entities)

            {

                userId = (Guid)team["systemuserid"];

            }

            service = factory.CreateOrganizationService(userId);

            #endregion