Some friends may be like me. The 4 GB memory used on the dell server cannot be identified. Let's take a look at the solution. Server: Dell™PowerEdge™860 system: windows 2003 R2 problem: Version 2003r2 is installed. 4G memory can be identified in bios. After the system is installed, only MB memory can be identified. [Solution] Go to BIOS and set "OS Install Mode" = "ON" to "OFF" to solve the problem.DELL4G memory not recognized by the server. [Analysis] determines the maximum memory capacity available for the operating system. "On" sets the maximum memory to 256 MB. Off enables the operating system to use all system memory. Some operating systems cannot be installed in systems with a memory capacity greater than 2 GB. Enable this option during operating system installation ("On" [On]); disable this option after installation ("Off" [Off]).