This may help another novice to resolve a KB974417 installation problem. The solution that worked for me on a stand-alone WinXP Pro SP3 machine goes like this. Using Add/Remove programs, remove all instances of .NET framework beginning with the latest version first. Reboot. Next use MS Update to check for updates and install the offerred updates, lowest version no's first, then security updates etc. ONE AT A TIME, REBOOTING BEWTEEN EACH UPDATE. I know this is cumbersome but MS Update will only offer some updates once the preceding ones are already installed. About 8 reboots were required I think.
