I have a Latitude D420. It has 500 MB built-in internal RAM as well as my 1 GB stick that I added. However, with the 1GB stick removed, I go into the BIOS and it tells me that there is 500 MB available but only 55 MB useable. When I add the 1Gb it tells me there's 1.5 GB available but still only 55 MB usable. I also get a memory error message when I switch the computer on.
I am unable to see how much RAM is recognized in Windows becuase the small 55 MB amount always causes the computer to blue-screen when I try to install Windows off aninstallation CD.
Any suggestions - is the internal RAM (and therefore the motherboard) dead, or is there hope for this laptop?
You have no choice but to locate and reseat that 500MB memory module. If that doesn't work, you either have a bad module or a bad socket.
It isn't possible to remove the memory. if it has failed, you will need to replace the mainboard - which includes the processor.