I don't know how this is possible, but it is. Any ideas? Start, right click my computer, properties, is only showing 256 mb of Ram, and PC is acting like it only has 256MB of ram. However, cmos shows the 3072 MB DDR SDRAM, speed 333MHZ, Dual, AGP 128 MB. Pentium 4, 2.80 GHz.. Level 2 cache=512 kb. Bios A07. I'm thinking of total cmos reset by removing and reinstalling battery? Bus Speed 533 MHZ, Processor F29.
Running Dell Support "has not detected any relevant problem"
Crucial System scan reports: 3 gb, but though it should work, I see I have one 1gb PC3200 and 1gb PC2700, 512MB PC3200 and 512 PC 2700. So, I looked at the 512MB , DDR, 333, CL2.5 by Infineon that is labeled PC2700U and it shows on the Crucial Test as PC3200, interest. So I removed it and replaced it with another stick that is labeled PC2700, 512. Cmos still reported it correctly on start up as 3 gb. Still only 256 MB of Ram is being reported. Ran the Crucial Scan again and this time, it is still showing another brand as DDR PC3200 that is not.
Next, I removed both 512 sticks and cmos reported a total of 2048 MB DDR SDRAM. Strange, froze on boot up. No keyboard and no mouse. Shut down, Unplugged 20 seconds and booted again. Double checked and cmos ok. This time it booted ok. Memory still reporting as only 256 MB of RAM.
Turned off, unplugged, and reversed position of the 1 gb memory sticks. No difference, still reporting 256 mb of ram.
Turned off ,unplugged. Removed 1 stick, let remain Crucial 1 gb PC3200U-30331-Z. CMOS showed correctly on startup. Still only 256MB of RAM showed.
Removed battery, cleared password, reinstalled battery, reset cmos data, Finally, now it shows I have 1gb. Finally,
Turned off, unplugged, installed 3 sticks of 512, PC 2700. Total memory on cmos startup shows 2,560, which is correct. Since these are not matched pairs, it will be interesting to see how they function. Properties now reports 2.50 gb which is correct.
Crucial scan now reports all memory correctly.
Bottom Line - if memory is wrong in properties, remove battery and jumper to clear password to correct problem. Now pc is behaving properly. If you experience the same problem, this should help, though it took a while to get there.