The system [Motherboard ECS 845GV-M3 with 2-DIMM-slots and Pentium 4 Socket 478 in Fry's white box GQ5080 running WinXP] has been running for 2 years with 256MB i.e. 1 module DDR PC2700 CL2.5 256MB. I upgraded the system last week with one Corsair VS1GB333G i.e. 1 module DDR PC2700 CL2.5 1GB. The system's Award BIOS only sees 256MB of the 1GB module i.e. BIOS sees only 256MB when only the 1GB module is present or sees only 512MB when the 2 modules [256MB & 1GB] are present. Seems to me that the BIOS limits the memory to 256MB per slot. Note that Memtest86+ only sees 256MB of the 1GB when only the 1GB module is present.
I searched for an "OS Install Mode" that could limit to 256MB [per slot?] but could not find it in Award BIOS. Any suggestion ?