You are in the process of adding additional RAM to your server, what should you do before you purchase more RAM?

A.
Identify the amount of RAM

B.
The RAM fits the system board slot

C.
Buy from one manufacturer

D.
Check that the RAM is compatible with the existing RAM

Explanation:
Memory issues rarely require a system’s BIOS to be upgraded. One possible exception would be when an available BIOS upgrade permits a greater amount of system RAM or it could be that your computer refuses to recognize that compatible RAM is installed.
Incorrect
Answers:
A: That is only decided when you know it is compatible and we do not.
B: Many different RAM types can be used in different slots but you should first make sure that is compatible.
C: This is okay but you must firstly determine what is supported and compatible with your configuration.
Reference:
Charles J. Brooks, Server+ Certification Exam Cram 2 (Exam SK0-002), QUE Publishing, Indianapolis, 2006, pp. 390.