If you wish to install Windows 10 64bit on a HP EliteBook 850 G1 Notebook-PC you need the following drivers:
Warnung: Some of the drivers below aren´t officially tested by HP with the 850 G1. However they work on my device without issues.
HP Ultraslim 2013 Docking Station
It you have something to update to the list, feel free to leave a comment
The latest WLAN standard which can be used officially is AC (from 2014) you require a "Intel Dual Band Wireless-AC 7260 802.11 ac 2x2 WiFi + BT 4.0 WLAN module". It should have the entry "SPS: 710661-001" printed on the sticker!