From http://autodesk.com/softimagemanualactivation

Software Retirement Notice
In order to maintain a high level of support for our Autodesk® Softimage® software customers moving forward, please be advised that historical versions of Softimage products (versions prior to Autodesk Softimage 7.5) will be retired effective August 1, 2011. If you intend to move a historical version of Softimage from one workstation to another, please do so prior to the retirement date to make sure that you will be able to re-activate your license.

To learn more about getting current with Softimage, please visit: http://www.autodesk.com/softimage.