Windows 7 RC default drivers for ATI Radeon Mobility X300 are working fine on my work Dell Inspiron 9300 with Aero Glass and all, but let’s try to push it a bit further.
Download Catalyst Radeon 9.3.1 legacy desktop drivers for Windows Vista x32:
Run the package and let it extract the drivers - usually to a path like X:\ATI\Support\9-3_1_legacy_vista32-64_dd_ccc – then cancel the installation.
Download and run DriverHeaven’s Mobility Modder to modify the drivers package (see similar notes on the application download page).
I’ve tried then to run the setup.exe from the driver package as the instructions say on the Mobility Modder page, but the driver didn’t show up in the list, so I went and update the driver manually through Computer Management > Device Manager > Display adapters > ATI MOBILITY RADEON X300 > Driver (tab) > Update driver > Browse my computer for driver software > Let me pick from list of device drivers on my computer > Have Disk > X:\ATI\Support\9-3_1_legacy_vista32-64_dd_ccc\Packages\Drivers\Display\LH_INF > etc. Reboot when prompted.
Note: I have tried the same procedure on ATI Catalyst 9.8 desktop drivers, and although the driver is being presented through the manual update procedure, on reboot I lost the Aero Glass and the maximum resolution allowed was 1600x1200. Which probably makes sense, since ATI has dropped support for the legacy chipsets in newer drivers, even if the Modder makes them appear in the .inf file.