Hi Black March,
There are possible reasons why it is not appearing on your laptop, such as it might already faulty, or your laptop cannot recognize the ram due to speed/specification mismatch (your laptop might support DDR4 and your ram stick is DDR3) or your ram stick memory is too big that the laptop's board no longer supports it, you'll be needing to check your laptop's maximum ram memory it supports then add the both ram stick memory and check if the combined memory size of your ram sticks exceeds the maximum memory your laptop can accept.
In case it is already faulty, I suggest to purchase a new ram that matches as well the current ram stick installed on your laptop.
