Hi Colleen123,
Welcome to the HP Support forums. I understand you need the drivers for your Officejet 4500.
I have included the link to the driver's download page. It should list the different models of Officejet 4500. Please choose the correct model of printer and it will take you to driver download page. Once there please choose your operating system to download the driver.
HP Officejet 4500 All-in-One Printer - Drivers & Software page
http://www8.hp.com/us/en/support-search.html?tab=1#/qryterm=officejet%204500&searchtype=s-002