Inspiron 1501MK36 AMD Turion2 GB RAMATI 200MSeries
Nvidia MCP 61 chipset is what is used in the Inspiron 531
Known drivers that work for the 531 and most likely the 531s, install the in the following order for best results.
1. Chipset, 2. Video, 3. Sound, 4. Modem, 5. AMDlive patch
As some of these nvidia links may become broken, you can get a complete nVidia driver pack here