Question about 3dmark 2000 (yes -2000)

My PC has been pretty sluggush lately and nothing I did was helping. So I decided it was time for a fresh install of XP.

I bought a MyBook for all of my save games, patches, utilites etc. After the re-install I was curious about how the benchmarks would fare, but like an idiot the folder I drug to the external only had the shortcuts for most of the benches in it. The only complete program was 3dmark 2000.

I had some trouble getting my interenet to connect so I just used 2000. Coming off of a fresh install running as one of the first apps it scored around 65000. I know 3dmark 2000 is antiquated but I was still surprised by how high the score was (and that was at 1680x1050 without the CPU test working). I remember back in the day being happy to break 20000.

So in the meantime I got my interenet working and XP started to install all of the updates (specifically SP2 and SP3). After all of the updating was done I decided to check again with 3dmark 2000. This time the scores dropped to around 31000.

Besides the XP upgrades all I installed was Avast anti-virus and Steam. Disabling both raised the score to about 33000 - still about 50% slower.

So my question is - Do Microsoft updates really cause such a slowdown? Or is 3dmark 2000 simply too old to be relevant?

I know there's not much difference between 1500 fps and 800 fps, but after the automatic updates some of the fps actually dipped below 100 on the high detail test. Before I think the absolute lowest I saw was around 120.

If you run 3Dmark06 and get around 13-15k you would be fine.