im on a dell dimension 2400-P4 2.66ghz - 2gbRAM - 500HDD on Windows 7 ultimate working perfectly.
this is what ive done on 3 pcs both dell.
1. extract chipset driver
and the intel extreme graphics to get this folders: R47822 or so.
2. run the setup file, 1st time it wont install cuz the os is not supported and the window should close, after that it should pop up a window with 2 options, if not try running setup again so it will apear the window, click on run or Use reccomended settings and this time it will work, dont restart computer yet.
3. install intel extreme graphics drivers
same procedure as step 2. and do not restart computer.
4. go to start - run - msconfig - BOOT tab - click on Os boot information
5. restart computer and enjoy.
hope it solves your problem.