Non-Support of Empl. Purchased HW

Hi everyone – I’m a Tech Manager for a major lawfirm with over 1000 machines. We are currently refreshing our inventory and will shortly offer the old equipment to our employees. How do you best suggest I impliment a policy of non support for this equipment. There is no current way to determine if it is old hardware or new hardware until the last one is refreshed. (constant cycle as you know). We’ve an outsourced helpdesk so that makes it even worse. Any thoughts or suggestions welcomed!!

Taylor