Windows 10: Why instead of the actually 4 GB ram, the systemTask manager says there is total 3.8 GB Ram?

Just a question became i used to think that if you have 4/8/any amount of Ram, then there will be the same Any amount of ramGb ram mentioned in the system, but i want to know why it says 3.8 instead of 4Gb, My guess is that it is used for some important windows process, but that's just my guess

:)

 

Ram upgrading: 4+4=8 gb or 4+8=12 gb?

I am using dell inspiron 5447

windows 10, 4 gb ram installed originally,

Intel i5, 2.4Ghz.

What would be better choice 4+4=8 gb or 4+8=12 gb?

 

16 GB of Ram installed hardware hijacking 8 GB of it.

Hi and thank you for your reply. Yes I have tried that (I forgot to mention that): fitting both Rams into slots 1 and 3 and both back into slots 1 and 2. Then I tried putting both into slot 2 to see if they worked and they both worked. Now when i go into
the BIOS, under memory, it says up at the top 8 GB of memory it is using I am thinking. Down to the right where it actually shows what is plugged into the slots where the ram is, it says: in one slot 8 GB and in the other 8 GB. So, to me it actually is registering
the two ram sticks in the slots but is only using 8 GB of memory and that's why it is showing 8 GB in the BIOS? That's what I am hopefully thinking anyway. I am going to look up on my keyboard on how to take a screen shot of my bios so I can show you and get
back to you. Does this sound right to you? Thanks!

 

Why 2.66 GB usable in 4 GB ram?

Thanks to everyone for their valuable suggestions. I guess the problem was with the OS.Because after increasing my ram from 4 gb to 8 gb still the usable memory was 2267 mb out of 8 gb, then I did a clean install of Windows 7.Now everything is fine and smooth, and usable memory is 7.9 gb out of 8 gb.