In our latest case in was obviously caused by the nvidia driver interaction with GeForce 310M on Sony VPCCW25FH. To resolve, follow the steps:

1. Immediately after first setup restart (before it is doing “Completing installation”), press F8 to invoke boot menu
2. Select Safe Mode
3. Setup will complain what it cannot continue in the Safe Mode, DO NOT press OK
4. Press Shift-F10
5. In the appearing command prompt type compmgmt.msc <Enter> and wait a while
6. In the management console go to device manager and disable video adapter
7. Close all windows and restart
8. Do not enter boot menu this time, let setup continue as usual