Triggering ondemand workflow from C# code

// Set up the CRM Service.
CrmAuthenticationToken token = new CrmAuthenticationToken();
// You can use enums.cs from the SDK\Helpers folder to get the enumeration for Active Directory authentication.
token.AuthenticationType = 0;
token.OrganizationName = "AdventureWorksCycle";

CrmService service = new CrmService();
service.Url = "http://:/mscrmservices/2007/crmservice.asmx";
service.CrmAuthenticationTokenValue = token;
service.Credentials = System.Net.CredentialCache.DefaultCredentials;

// Create an ExecuteWorkflow request.
ExecuteWorkflowRequest request = new ExecuteWorkflowRequest();

//Assign the ID of the workflow you want to execute to the request.
request.WorkflowId = new Guid("b050f053-6968-dc11-bb3a-0003ffbad37a");

//Assign the ID of the entity to execute the workflow on to the request.
request.EntityId = new Guid("1DCDEE97-35BB-44BE-8353-58BC36592656");

// Execute the workflow.
ExecuteWorkflowResponse response = (ExecuteWorkflowResponse)service.Execute(request);