bios and memory slot reading

Nov 2, 2018
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i have msi z77 mpower , its not new one

i use 2 memory stick in slot 1 and slot 2 , why because the mother board only read these slots

when i check the bios for the memory slot in used it says , using 3 and 4

so what is this Removed , and how i can fix it , or should i break this Removed board , and rest assure