If Leveno has approved your laptop for the Win8.1 upgrade, they will have drivers for it. Go to their support/downloads and get the correct drivers. Keep in mind that not all laptops are Win8.1 upgradeable...even if they run Win8 with no issues. Also check for a bios update.
Intel I7 960 @ 3.87ghz *Intel DX58SO *HIS HD6970 2gb *Corsair TX650M *2x4gb Corsair XMS3 *WD Black 1TB *Windows 7 Home Premium 64bit ***Asus N71Jq laptop *Intel I7 720QM Processor *Mobility Radeon HD5730 1gb *8gb Ram *Windows 7 64bit ** Toshiba P75-A7200 * Intel I7-4700MQ * Windows 8.1 64bit
* A clear conscience is usually a sign of bad memory *