Intel’s official site no longer hosts this driver directly. Instead, search for “Intel G33 G31 driver” and you will be redirected to Intel’s Download Center for Legacy Products. You will find a file named: win7_1512754.exe . This is the last official version.
If you find the driver hunt frustrating and your performance needs exceed 2D office work, consider adding a low-profile discrete GPU. Even a $20 used or Radeon HD 6450 (both with Windows 7 drivers) will outperform GMA 3100 by a factor of 5–10x and offer full Aero, 1080p video decoding, and even light gaming. intelr g33 g31 express chipset family driver windows 7 best
Visit the official or your motherboard manufacturer’s support page (e.g., ASUS, Gigabyte, or Dell). Search for "G31 Windows 7 Driver." Download the .exe file. Intel’s official site no longer hosts this driver directly