John,
This is normally caused by something that is stuck in the PendingReboot
key. If you would like to contact me directly, I can provide you a tool
that may assist in discovering what is there causing the issue.
(timmac@microsoft.com)
You could also, browse the contents of the Prerequisites CD and install
each individual item seperatly. Keep in mind, based on the operating
system, that you may not need all of the Prerequisities.
Cheers,
Tim Macaulay, MCSD, MCP.Net
Microsoft Product Support