Welcome.

OK.

All of the Critical Updates, and keep going back until no more are offered.
Then, I usually take all the Optional updates, unless space or specs are a
concern. For instance, I wouldn't put .Net Framework on a p200 with 4GB HD.

Right there at Windows Updates.

I'm sure there is that someone has a script that looks in all the right
places. But in Windows 98 au natural, the list is spread all over the place.
Add/Remove Programs, MSINFO32, various places in the Registry. Easier if you
have a script that looks where it knows it should find something if present
(and maybe even check to see if it's intact.) SOmeone else should be able to
answer that.

That's an older place, and while you're there, I would download all those,
JIC. However a more complete list of stand-alone Updates is at Windows
Update Catalogue. At the Windows Updates site I linked to above, use
Personalize. Enable the Catalogue, then go to the Catalogue. Find the
appropriate OS and search for the downloads. Be sure to collect the ReadMes
while you're at it!

For now, yes. Depends on how deeply you want to get into the subject of
updating. You now have the info you need for maintaining your system. THe
rest is academic.

You're Wellllllcommmmmmme!