Yes they do keep me busy :) but I really like to help all the way to the end. In this case, you are right as they build up from previous drivers to work with current ones and depending on the date the printer was released can also determine how long they hold onto that driver's compatibility with older operating systems. Also, after 5 years, certain things on the website simply become obsolete.
Here is a Deskjet 990c driver for Windows 2000. Here is a Deskjet 6980 driver for Windows 2000. Both you can download and at least one of them should work. Let me know if this helps you any!