The driver cab is basically the SYSTEM32\DRIVERS directory, you need the inf files too, they are already in the \INF directory so you should be able to use them.
Hi, I wonder if anyone ever succeeded installing a graphics card in Windows PE, i tried to do this with devcon.exe and tried hwpnp too, as far as i know it is possible to install the driver, but how can we apply the new driver without rebooting?