>After I installed IIS, I didn't reinstall Win2K SP3 as, by default, I assumed that windowsupdate.com, who recognized that new files were available to patch IIS, would have taken care of it. Did I assume right? If not, does this mean, I have to reinstall SP3 again in order to fully patch IIS?

Hi Michael.
You definitely have to reinstall SP3 after such a change as installing IIS
Windows Update does not check every dll against the Service Pack file list, it just checks if its installed.

Regards
Jose.