Reinstalling upgrade CS5.5 on a new computer,

When I inserted the CS5.5 upgrade disk it asked for previous key, entered it, said software was not installed, downloaded and installed CS3 from accounts.adobe.com, no issues on download or install, put in CS5.5, said entered key not valid key or upgrade path, downloaded and installed InDesign 5, purchased 2010, same message. CS5.5 upgrade was installed with both of these apps on an iMac 21" and runs okay.

How can I get this working on the new computer.