There is a huge bug on current Elitebook generation. I checked 860 model in detail and it doesn't allow you to upgrade or even replace RAM even by user manual it should be possible by customer. I tested it with different 860s, different RAM brands. Even replacing the originally built-in 16 GB Samsung 4800 MHz DDR5 single rank by exact the same but new on - it doesn't work. Num and Caps Lock always blinking 5x which means memory issue. I'm IT technican and tried reallly everything. CMOS reset doesn't help. It is blocked by HP even it should be replacable by customer. The funny point ist, that 860 (Intel CPU) and 865 (AMD CPU) are the same laptops just with different CPUs and on 860's user manual RAM upgrades are listed as "customer self-Service" and on 865's user manual as "only by authorized HP service". It is a huge bug HP, fix it ASAP!