Latitude E7470 Memory issue

We recently purchased 6 new Latitude E7470 laptops.  The laptops originally come with Windows 7 64 bit OS and 4GB RAM.  We have application only works in 32bit OS.  We wipe the OS out and reloaded the OS with Windows 7 32bit OS.  With all the drivers loaded up, everything seems to be working properly.  However, when we looked at the system properties, it shows the installed memory is 4GB, but the usable memory is only 1.98GB.  Under the task manager, it also shows 1.98GB memory.  When we go in the "resource monitor" inside the task manager, it shows the physical memory is 4GB, but the "Hardware Reserved" memory is 2GB.  That leaves only 2GB usable memory to the OS.  By compare to another E7470 laptop with 64bit Windows 7, the hardware reserved memory is only 128MB and leaving 3.89GB memory to the OS.  We originally believed that is the memory module on that particular laptop.  However, we installed the 32bit OS on anther laptop and have the same result.  That is not a problem with the RAM module.  After that, we checked the BIOS version on the laptop which is on verion 1.0.1.  We upgraded the BIOS to the latest 1.2.2 version and rebooted the computer.  After the BIOS upgrade, the memory is now showing 2.5GB in the task manager and compute properties.  So the BIOS upgrade released another 0.5GB to the OS but it still not giving the optimal level of available to the OS.  I called the support with the case 925640096.  The support insisted that is normal behavior for the 32bit OS.  I would accept that answer if the BIOS upgrade DIDN'T increase the available RAM.  However, the BIOS DID make the change but it didn't make to the optimal level.  Personally I believe that is the BIOS somehow withhold additional memory for unknown reason.    Does anyone have this same problem or know how to get a hold with the DELL hardware developer to have them diagnose the BIOS?