Live Update problem and piupdate problem

I have NIS 2008 and Live Update will not update all my  'products'. I think that my catalog file needs rebuilding and have found a utility that may do this in the "Live Update with no new updates needed - HELP" post solution. The poster  had the 2005 version so I hope this is the right solution..

 

I clicked on the link to use or download the utility and got a LU1825 error message saying that the update was corrupted and Live Update could not process it. I downloaded piupdate.exe to solve this problem.  However, when I try to run piupdate.exe I just get a message to say that it is not a valid Win32 application.  Account user control does not ask me to allow it to run..  I have tried getting it to run as administrator but that does not work.  My OS is Vista.

 

Can anyone help.  Unfortunately, because of another problem, updating to a newer version of NIS is not an option for me.