Available 3.98 out of 8 GB of RAM.

Windows 10, 64-bit processor is also 64-bit. Method: In the boot tab, uncheck does not work because the checkmark was removed from the beginning. In the BIOS there is a function memory hole remapping if it is turned off, already writes: is Available from 3.23 8 GB of RAM. How to include it, again, writes: is Available 3.98 out of 8 GB of RAM... why?