This is probably going to sound a bit daft, but I would quite like to sort this issue.
I have just been given an old Toshiba Tecra 700CT, circa 1995. I quite enjoy messing with older stuff, so I wanted to try getting Windows 98SE on it (currently a messy 95 install).
The system has 16Mb non-removable RAM as standard, but has the optional 32Mb module installed. When the system boots it does a quick memory count, with the 32Mb module installed it is only seeing that 32. If I remove it and boot, the system sees 16.
I have tried resetting the BIOS settings, but this just made it redo an extended memory check. I have checked the part number and this module is definitely a 32Mb module. The service manual for the machine suggests that I should be seeing 48Mb with the module installed.
I realise this is probably a bit of a long shot, but I'm hoping I have just missed something obvious on this older system, and someone out there knows what it is.