Hey guys I have changed the Hard Drive for my HP Pavilion ze5500 and cannot find the CD to install the operating system.I still have the product key lable on the back of my laptop. Is there any way I could burn the windows XP operating system for this particular model on CD online. Thank you any suggestions and help would be greately appriciated...

You can get the XP recovery disc directly from HP.
Here's te information: HP Notebook PCs - Order Recovery Discs for Windows 7, Vista, or XP - c00810334 - HP Business Support Center

Thanks a lot. Your suggestion was greatly helful to me!