Can't install Airport utility on MacbookPro

[bigskydog2004]

I'm trying to configure my Airport Express as a wireless print server.

I inserted the Airport Express cd (approximately 21/2 years old) started the installation and got the message,

"You cannot install AirPort on this volume. The version of Mac OS X on this volume is not supported." when I attempted to install to the HD.

WTF I'm running OS-X 10.5

Any ideas what I am overlooking???

Thanks

 

[waw74]

Airport utility 5.5.1- Requires 10.5.7 or later

Airport utility 5.4.2- Requires 10.4.x or later