"Properties" inaccessable after bad W2K SP3 install

Originally I purchased an edu version of Microsoft .Net Dev Studio in order to use Vis Basic and latest VC++. Attempting to install, it said I needed SP3 and the 3 latest security bugfixes, Which I downloaded over a 56K modem for ~12 hours over 3-day period. I then installed them, and attempted to install .Net again and was informed that I was still missing the required security bugfixes! Thinking I had not gotten a clean install, I attempted to uninstall them (in order to re-install) but I didn't know the order they were installed, and apparently uninstalled them out of order.
...After numerous re-installs of W2k, I finally got MOST of it to function again, except Properties--Right clicking on any non-windows file folder, say on the desktop, or anywhere else, for that matter, brings up the usual menu, but clicking on "Properties" does absolutely nothing! Nor does Properties work from the File menu.
Short of wiping the HDD, is there anything I can do? Is it possible to completely uninstall W2k without wiping out the file structure of the other programs? If so, how can I get a fresh install of W2k to recognize them? Thanks in advance for any help you can give me. BTW, the undocumented Properties disabler tweak in the registry after (successful) install of SP3 is apparently not present, at least not where it is purportedly supposed to be (I don't remember exactly where that is just now, other than "...\software\microsoft\...") so this isn't a quick solution to the problem.