It could also be useful to know the name of your mainboard. Usually there's a name and product identification near the socket of the processor, or between parallel slots under your video card (assuming it's not an integrated model)

Intel Pentium G4400 dual core CPU.
Crucial 8 Gigabytes DDR4-2133 single channel memory.
Gigabyte GA-H110M-M.2 Motherboard.
Toshiba DT01ACA050 500 Gigabyte OEM hard-drive (ripped out of an HP Pavilion)
HP DVD-RAM SW830 Optical Drive (It is actually quite fast, also Ripped out of the HP Pavilion.)
Antec VP450 450 watt power supply. 
Foxconn PVA092G12M DC Brushless Fan (Ripped out of the same HP Pavilion).
Gateway 310 N Mini Tower Case. (It's 13 years old)
I also plan on eventually getting a GTX 1050, but until then I will be running on the G4400's Integrated Graphics.

Marko S. wrote:

Source of the post I noticed that it was showing 8 gigs of ram but only 3.96 gigs usable. I was like "How can this happen?"

Yesterday I had a friend who had the same problem, although he spent a considerable amount of time with his head contacting the keyboard at high velocities.

HarbingerDawn wrote:

Source of the post Re-seat the RAM (remove it and put it back in). If that doesn't work, it's possible that some of your RAM is bad.

Going to try that later. I tried to fix this problem by going in msconfig then in boot, advanced settings and unchecking the maximum memory. I can't enter now the properties and see if it sill uses 3.96 or now it's using 8gb. Everybody said that this is the best solution on youtube and other sites and it worked for others. I doubt that it worked since in task manager it is saying I have 8gb but in that graph it says 4gb in memory tab.
I have been using same RAM since I bought the computer. Maybe it is damaged since there has been a lot of dust. Never cleaned it so... Don't know. That was first cleaning for this PC.

Mosfet wrote:

It could also be useful to know the name of your mainboard. Usually there's a name and product identification near the socket of the processor, or between parallel slots under your video card (assuming it's not an integrated model)

I now can't find the information but I think it is MB FM2+, PCIe/DDR3/SATA2/GLAN/7.1 or something like that. I have also DDR3 RAM memory.


I will update you if it is fixed. I never took the RAM out of motherboard so this will be the first time. I will first try to clean it better since I didn't do that yesterday. I don't want to mess up. I will also do other things. It is saying in resource monitor 4gb hardware reserved.
Thanks for helping, guys!

EDIT: I also tried changing some values in Registry files and didn't work. Didn't do something probably. And I forgot to tell you it is on 1600 MHz.

Marko S. wrote:

Source of the post It is saying in resource monitor 4gb hardware reserved.

Usually it means that Windows is reserving memory for the integrated video card, even if it's not in use. Your Gigabyte motherboard does have an Intel HD Graphics card onboard, but with a maximum shared memory of 512MB, which is strange, but... You should check your BIOS/UEFI setup and see if you can disable the integrated card. You could also try by disabling it via Windows computer management.

Try what HarbingerDawn suggested first, anyway.

Mosfet wrote:

Marko S. wrote:

Source of the post It is saying in resource monitor 4gb hardware reserved.

Usually it means that Windows is reserving memory for the integrated video card, even if it's not in use. Your Gigabyte motherboard does have an Intel HD Graphics card onboard, but with a maximum shared memory of 512MB, which is strange, but... You should check your BIOS/UEFI setup and see if you can disable the integrated card. You could also try by disabling it via Windows computer management.

Try what HarbingerDawn suggested first, anyway.

I don't know if that motherboard I typed is the correct one since I just copied it from the site I bought it. It has passed 3 years since I bought it so they probably changed motherboard and processor. I have AMD Radeon R7 250 Series graphic card. so I don't know if I typed wrong motherboard or you got it wrong. It has 1gb.
Anyway, I will try that. Now I am not at that computer at the moment. It will probably fix the problem since it will clean of the dust at the same time.

HarbingerDawn wrote:

Source of the post Re-seat the RAM (remove it and put it back in). If that doesn't work, it's possible that some of your RAM is bad.

That didn't work... I removed it and put it back on. Maybe I should do it again since I there is still dust on slots. I have 2x4 DDR3 GB of ram. Should I just remove one ram stick and see if that's the problem with one ram. But what would happen if I remove a healthy ram, but that where is harware reserved is on? It says 4gb hardware reserved and it is anoying since I tried a lot of things to fix it. Should I remove and place it in again? I currently don't have money to spend on new ram. 
And thanks for helping!

Marko S. wrote:

Source of the post Should I just remove one ram stick and see if that's the problem with one ram

yes, for both sticks one at a time.

Marko S. wrote:

Source of the post But what would happen if I remove a healthy ram, but that where is harware reserved is on?

Nothing. The OS will adapt.
Did you check if your integrated Intel HD graphics is disabled?

Mosfet wrote:

Source of the post Did you check if your integrated Intel HD graphics is disabled?

I checked, and I don't have any Intel graphics. I could tell that you even if I didn't check. But problem is still here. I rarely go in BIOS so I don't know much stuff going on there. Maybe something with shared memory as you said? But with my AMD Radeon R7 200 series graphics card. I really don't know what could cause 4 gigabytes of hardware reserved memory.

Mosfet wrote:

Source of the post yes, for both sticks one at a time.

I still haven't tried the sticks one at the time. Maybe it will fix the problem if I change RAM from one slot to another and again with other one. Maybe problem is not with RAM, maybe it is with slots. Still don't know.

HarbingerDawn, Mosfet, Good news! I fixed the problem! I removed both RAM sticks. Then, I put the first one in the another slot, and then I did that for another RAM, I set second in the first slot where was that first RAM.

Marko S. wrote:

Source of the post Maybe it will fix the problem if I change RAM from one slot to another and again with other one.

Looks like I guessed right.

The Potato wrote:

Source of the post Yesterday I had a friend who had the same problem, although he spent a considerable amount of time with his head contacting the keyboard at high velocities.

So, if he is having the problem and nothing is working, tell him to try this method.

Here are my current specs:

Intel i7 4790k Devil's Canyon, Quad-Core 4.0ghz
16gb G.Skill DDR3 (pc10666)
8gb EVGA Gefore GTX 1070 SC Gaming ACX 3.0 Black Edition
256gb Crucial CT256MX SSD (OS drive)
2x 276gb Crucial MX300 SSD (RAID 0 for large games/fast access of large gaming files)
1x 2tb WD20EZRX Green (data/games)
1x 300gb WD3000HLHX 10k rpm Raptor drive
Windows 10 Ultimate x64 Edition (least I think it was the ultimate edition I chose)

Stock cooler, no water cooling, idles at 30 degrees (using the Antec Twelve Hundred V3 gaming case from when I had seven hard drives stacked in the front of it... airflow and cooling was at a premium at that point, heh).

Windows 10 its probably super bad compared to other PC users.

I'm having a new system built by a company called Portatech that I should be getting in January.  It's built around a Core i7 and has a 4 GB Geforce card, I'm going to update this post with specs - it's going to end up costing me about $1200.  I would like some input into whether this is a good price I'm paying for a custom system or am I overpaying here  Thanks!

Order Summary

QtyPrice

Remove
$1,176.65Complete System w/ Intel Core (Socket 1151)
w/ Core i7 7700 (4 x 4.0GHz CPU - 8MB Cache +HD630 Graphics)
Asus ROG-STRIX-H270F
8GB DDR4-2400 
Ultra Cool Package
120GB Solid State Drive (SSD)
2TB Hard Drive - 7200RPM
24X DVD+/-RW Drive
Thermaltake OpenCool Mid Tower Case
700W - Power Supply w/ Active PFC
Windows 10
nVidia GeForce GTX1050 Ti - 4GB
Standard - Build, Burn-in, Test & Ship Out in Approx 3 to 5 Business Days
1 Year Warranty

Remove
$6.75Platinum Deliv. Plan (Full Insur - Heavier Pkg - On Time Guarantee)

Remove
$64.95C.L. Sound Blaster Audigy RX 7.1
Subtotal:

Sales Tax (CA Only):

$1248.35

$0.00

$19.94 FedEx Smart Post - 3 To 5 Business Days In-Transit

SE consuming 3gigs(25%) of main RAM and 8 gigs (100%) of VRAM:

CPU utilization is a mere 8%.
I am quite happy with my 7-year old PC:

I only fear the day my motherboard will die. So I am saving for an upgrade:
CPU: i7-7820X
Motherboard: MSI X299 RAIDER LGA 2066 Intel X299 SATA 6Gb/s USB 3.1 ATX Intel Motherboard (Cheapest 2066 solution)
and RAM: any quality brand [email protected] 4x4GB DIMMS total 16GB (I don't think anything more then that is necessary for gaming - I only play SE and Elite: Dangerous)
Total cost ~ 1000-1100 Euros
I am keeping my 2SSDs, GPU (GTX-1070), case and of course a 1200Watt Corsair PSU.