To cancel (manually stop) a process instance, do the following.
    
    Note that it is also possible to cancel a process instance using the Process Instance List
      web part in SharePoint.
      
      
      
      Prerequisites
 
         
         
          - A process instance in any status other
				than Completed or Canceled. 
			 
Navigation
 
		   
		  Find the process instance you want to manage: 
		  
 
		   
			 - On the Enterprise Manager Main Page, click
				the 
				Processes link. The 
				Processes page appears. 
			 
- Click 
				Find. The 
				Find Process(es) page appears. 
			 
- Enter the search criteria for your process,
				and click 
				OK. The processes that match the specified criteria are
				displayed. 
			 
Instructions
 
		   
		   
			 - In the search results on the 
				Find Process(es) page, select your process instance. 
			 
- Click 
				Cancel. 
				 Once a process instance is canceled, all assigned tasks will
				  be removed from the participants' task lists.