Kazaa unhandled exception

In my ongoing quest to learn more about computers, i find myself to be a little dumber than i thought.
This computer once had kazaa on it. Ive uninstalled the software and Hkey. But yet when i download the current verion of Kazaa i get an error message when the installshield starts. this is the message : Unhandled Exception Error number: 0x80070725 incompatible version of the RPC stub.

I have no clue what this is… can someone please quide me thru this. also i am parting out some older computers to build 1 working one. are there any sites that may help me learn more about the total workings of computers.
Thank you ahead of time from a total braindead user.
Rob