I partitioned the hard drive and attempted to install XP professional, however,I get the message that the OS is a later version than XP, therefore XP cannot be installed.
Windows XP no longer has any support, unless there is a game that only runs only under it there is no reason to use it. Some partition managers such as Partition commander allow you to hide the partition Windows 7 is on and will allow you to do the installation. You will need something like Easy BCD to allow you to dual boot after you unhide your Windows 7 partition. If you had Windows 7 Professional or Ulitimate version you can run business programs in virtual PC mode of XP.