What OS? Win 98/ME or Win XP?
What service packs you use?
Here's how to find out:
Find the START button in windows on the lower left of your screen
click SETTINGS
CONTROL PANEL
if Win XP click CLASSIC VIEW
else any other OS version now shows:
SYSTEM
click system, GENERAL has your service packs
If Windows XP, you'll want to know if it says Service Pack 1 or 2. If you have a legit copy of Windows, you can close control panel now and click HELP, then Windows Update.
----
Now, back to your question:
START
RUN
CMD <-- for Win XP
or
COMMAND <-- for Windows 98, Millenium
DXDIAG
then say NO to question "do you want DXDIAG to check if your drivers are digitally signed by Microsoft?" Phooey, MS charges graphics card companies $50,000 USD to check their drivers for them, it doesnt guarantee anything but so that consumers dont whine.
Much more important is the next screen, where it lets you see whats loaded...
Down below on your taskbar is a new program called "DirectX Diagnostics". Open that up.
Under SYSTEM tab you see what DX version you're running, how much RAM the system thinks you have, your page file size etc. Its all good stuff for tech support (I did tech support for 20 years before retiring). Get to that point and you're 90% there.
You certainly need to know what OS you are running (you'll see it back in the control panel steps, not in DirectX Diagnostics. From there you can know whether you have all the OTHER pieces DirectX expected. By the way, I couldn't update DirectX 9.0c from MS update site either, when I already had a development download of DX 9.0b installed. When I used the DX 9.0c that came on the EQ2 CD, I was OK. Good luck