*It's common that the update has to come from the LAPTOP MANUFACTURER, not from NVidia itself.
However, NVidia implies that they have a reference driver that SHOULD work:http://www.nvidia.com/object/notebook-win7-winvista-64bit-301.42-whql-driver.html
My advice is:
1. uninstall any current NVidia drivers completely
2. try the above driver (if it fails, try the latest one from your laptop support site)
1. update BIOS if new one exists
2. test RAM via Memtest www.memtest.org
3. update any other drivers as needed (from your laptop support site)
Let us know how it goes.