I successfully installed Mountain Lion GM on my Dell Inspiron 1720 with X3100 graphics. I used a ton of custom files to get the USB installer to load. When I ran the installer, it gave me some errors but I disregarded them. I copied the S/L/E folder from the USB installer to my ML partition along with the Extra folder. The ML installation booted up successfully the first time I attempted to boot up and I was able to successfully create an account and use iCloud to sync with my other devices. Good luck using these. If you're trying to install on a different laptop with different specs, don't expect the DSDT file to work well for you. I still have problems getting the laptop to wake from sleep and to shutdown/reboot. I am using Coolbook for speedstepping. This is still a work in progress.