MPHC audio issue.

Note that I just built this computer and upgraded to Windows 10 soon after. I can't comment if it was a Windows 8.1 problem, thinking it's a problem with 10.

On Media Player Home Cinema, sometimes whenever I play an audio or video file, the sound cracks for a second. One quickfire second, I find it hard to describe the sound. Think of playing a CD with wear and tear on it, it goes well until it buffers for a bit, in my case, just a second.

It's minor and I asked about a solution, being pointed to latencymon, finding out that my Atheros driver and dxgkrnl.sys had the most problems. The former gave out a lot of DPC routine thing, the latter with ISR issues. So I uninstalled the Atheros thing and stuck with the base drivers, and the solution for the latter was to disable CPU throttling. I assume that means on Power Settings, selecting "High performance." I did and for the most part, the problem stopped. However sometimes when playing something for a long continuous time, say a 90 minute movie, the problem returns. Is it possible to fix this problem permanently? Is it Windows 10's newness and how tough drivers have it to adapt? I updated all my drivers, I believe. Running on Realtek HD audio, which I'm sure is updated, according to ma-config.

Lastly, I never had this problem when playing a blu-ray through Power DVD, or VLC. I think on VLC, I haven't used it extensively.

Check if a BIOS update is available for your motherboard.

One thing that you could try is:
MPC-HC options > Playback > Output > Audio > Internal Audio Renderer
MPC-HC options > Interal Filters > Audio Renderer > Exclusive mode (but try with default settings first)

What's Internal Audio Renderer? I have it set to DirectSound: Speakers (Realtek High Definition Audio). I'll see what happens with audio renderer in exclusivve mode. Bios updating, I'm not sure. ASRock, the brand that made this motherboard, don't recommend if the system is running normally, and I don't want to risk problems during updating.

BIOS update should be relatively safe. And now you still have warranty on everything.

I updated BIOS and tried what you suggested, but I don't like the exclusive mode, it cuts off sound for other programs. I'm not sure if that particularly solved the problem, but going back to normal settings, even with updated BIOS, still made the problem occur.

And I tried on VLC, it happened there too. So it's not an MPHC specific issue. I haven't watched streamed stuff for long, so I can't tell if it happens while on Youtube for example.

Since disabling CPU throttling helped (a bit), maybe increasing process priority helps as well.
Press Ctrl+Shift+Esc to open Windows Task Manager. Right-click on mpc-hc64.exe (during playback of course) and set priority to high.
In case this actually helps, then there are tools (Process Lasso) for adjusting process priority automatically.

Another thing you can try is to Disable High Precision Event Timer (HPET). Here is some info:
http://forums.guru3d.com/showpost.php?p=3770113&postcount=2

I'll look into these, thanks for all the help, but I'm finding out that maybe switching audio outputs worked. The problem happened through Realtek HD on the PC. In the TV, connected via HDMI, the driver for that is NVIDIA's HD audio. So my earphones connected to that, haven't gotten a stutter so far. Played 2 movies in full.

I saw a solution where someone uninstalled Realtek's drivers, and it worked.

Earphones connected to the TV? Or does it also work when connected to the PC (after uninstalling the driver).

Maybe it will still work if you re-install the driver. A lot of problems that people have after updating from 8.1 to 10 seem to be fixable by simply re-installing the problematic software/driver or doing a clean install of Win10.

I haven't uninstalled the driver yet, and I have re-installed it, multiple times. No way I'm doing a clean install, if that involved formatting. It does, right?

No, it can be done without a (complete) format.
Settings > Update and Recovery > Recover > Refresh

Files/documents are kept. But you do need to re-install all software.

How can I disable HPET on my bios? Running X99X Fatal1ty Killer from ASRock

I have checked the manual of that mobo and I didn't see an option for it, so its probably always enabled in the uefi bios.

But disabling it just in Windows should be enough.

I disabled it, and maybe that decreased the occurrences, but it didn't outright stop it. Just got one. I tried uninstalling the Realtek HD audio driver, but after a later restart, it comes back.

Here is a tool from Microsoft to disable automatic driver updates:
https://support.microsoft.com/en-us/kb/3073930

What also can help is to disable functionality of your motherboard in the BIOS that you do not need. For example WiFi or Bluetooth.

I don't see any bluetooth or WiFi to disable, nor anything else. I'm not sure now, I've had two instances where there was a stutter. I think, they weren't as obvious as the previous ones.

About refreshing Windows, I've tried that a few times and got an "inaccessible boot device" message, reverting the changes so it's like the refresh attempt never happened.

Possible solution:
https://www.product-reviews.net/down/windows-10-inaccessible-boot-device-error/

In case you ever want to do a clean install:
https://www.microsoft.com/en-us/software-download/windows10

I'm confused, do I have to switch to IDE mode or RAID mode for my SSD? It's running on AHCI.

The correct value is AHCI.

What seems to work for some people is to use the same value as what was used during the installation of their current version of Windows.

You will get a lot of results if you Google for: "inaccessible boot device" "Windows 10" refresh. There might be other helpful tips.

I refreshed the OS, and it still happens. Rarely now, but it just happened. So far it's happened 3 times at least, I think. I can confirm it happened a few minutes ago. Someone in HP's support forum singled out the problem being NDIS.sys and TCPIP.sys. I'm thinking this is just a Windows 10 problem, it can't be anything else. So I hope an update comes to fix this.

Those are both network related. Your motherboard has two ethernet ports, right? One from Intel and one from Atheros. Try disabling one of the two in the Device manager.

Did you have any network activity (like a download) when the problem occurs?

What do you mean by network activity? I download things all the time, and the problem would come up or it won't during downloads. I do have two ethernet ports, I'll disable the Intel one, it rarely works for me anyways.

I mean a download during playback. DPC latency can increase with lots of activity (high download speed).

It does not seem to be a problem specific to Windows 10. If you search the Internet for "dpc latency network" you will find similar problems for older Windows too.

Same thing, I download during playback all the time, and it doesn't always happen then. I never had stutters on Windows XP.

Interesting topic:
http://www.techpowerup.com/forums/threads/guide-turn-your-killer-e2200-nic-into-qualcomm-atheros-ar8161.198899/
Driver 2.1.0.21 here:
http://www.driverscape.com/download/qualcomm-atheros-ar8161-pci-e-gigabit-ethernet-controller-%28ndis-6.30%29