armon

How to troubleshoot RAM compatibility issues on a Dell Optiplex 780?

 
I have a Dell Optiplex 780 that I want to upgrade to run the latest version of Windows 10 smoothly. I received two 4GB DDR3 Kingston HyperX Fury RAM modules from a friend who used them in his previous PC without any problems. However, when I installed them in my Dell Optiplex 780, the system did not recognize them and emitted a beep code. I tried different slots, cleaned the contacts, and reinstalled the original RAM, but nothing worked. What could be the cause of this issue and how can I resolve it? Is there a specific RAM requirement or configuration for the Dell Optiplex 780 that I am missing?
 
https://technsight.com/