I have an old IBM ThinkCentre 8189F1U desktop computer that I recently installed new memory into. It is running Windows 7 Enterprise 32-bit OS. I did have 2GB of ram which was detected correctly but after installing new 4x1GB sticks, the BIOS only detects 2.3GB. Windows 7 sees 4GB but only 2.3GB is usable. The BIOS is Phoenix Firstbios version 2AKT51AUS 7/6/2005. I have not been able to find an update to this BIOS. The MB is an IBM FRU PN 13R8926 and the documentation indicates it will accept 4GB of memory. The new ram conforms to the system specs also. I would appreciate any ideas. The system constantly uses the hd with only the 2GB installed.