I had 88 pieces of HP 840 G2 laptops. On one of them I installed Windows 7 with updates and drivers and cloned whole hard drive (all sectors) to the rest of the laptops. According to this topic - if it's the same model, it's safe: Can my laptop's Hard Disk be cloned and loaded to another laptop? Now some users have problem with blue screens. I know they are associated with wireless network card. There also was no Microsoft Virtual WiFi Miniport Adapter detected. I uninstalled the driver and installed it again and it helped, blue screens disappeared and two Microsoft Virtual WiFi Miniport Adapter items appeared in Device Manager. If it's safe to clone HDD, why do I have problems with it?
Now, I clone HDD differently. I use Sysprep with "Generalize" option to clone OS with updates and I add drivers to WIM image using DISM. I didn't see any blue screens yet, but again OS didn't detect any Microsoft Virtual WiFi Miniport Adapter, so I'm starting to worry that it's the same situation. Also there's C:\Windows\Temp folder taking whole free space after some time. I had the same problem when I was cloning HDD without Sysprep and DISM.