16gigabytes installed only 3.95 usable

Dmasterman said:

as another user said, in my system it states it's 64 bit.... so it is in fact a 32 bit?

We don't know yet.

Go to Control Panel.

Poke "system".

Post a screen shot of what you see.

Here is mine, indicating 64 bit next to "system type". Do you see that?

Verify that your memory meets the specs of your motherboard and cpu.
Then check your motherboard manual to verify the ram is installed properly.
Set your bios to default.

Again another picture I would like to see from your computer.

From Task Manager/Resource Monitor.

Damn look at that hardware Reserve, HUGE.

That most of the time indicates these things.

1. Wrong and/or mismatched ram
2. Ram setting way off. Timing, speed, voltage.
3. Just plain installed incorrectly.

Okay that's even a more bazar screen shot = Hardware reserved is soaking up nearly all your ram

That is odd, my board only uses 63 MB for hardware reserved.

Every board is different, but 12 GB for hardware reserved ???

Somethng is not right there Dmasterman

Funny on my Acer it shows 1mb hardware reserved

Dmasterman by chance have you been into Advance Boot Options?

Looks like this.