That would be DirectX 7 & 8 territory. There are a lot of good games you could try at that level.
Are you using a netbook with an atom proc. Intel offers a support page for getting the most out of these chips and has fixes for many issues.
http://www.intel.com/support/ (you might have to hunt around a bit)
Try these...
*Fallout 1 & 2.
*XCOM Apocolypse. Awsome.
*Balders Gate & Icewind Dale series. Excellent RPG 10/10
*Operation Flashpoint. Might be a push. Original only, the expansions might bog your sys down.
*Sacred. Another RPG like Diablo 2.
*Earth 2150. Sci Fi RTS. V Good.
*The Sims 1.
*Close Combat series. RTS WW2
*Hearts of Iron 1 & 2.
*Sudden Strike series RTS WW2
Man I could go on all day about the classic not crappy DX7 & 8 games. There's hundreds. Hope this helps a little.