On my large project I usually play back with 512 samples. Yeah, I know. Anything less is potential drop-out risk.
 
So I went into System Devices in Device Manager and, yes, I have *two* High Definition Audio devices, and a bunch of audio-related NVidia devices under "Sound, Video, & Game controllers".
 
So I disabled all of them, and rebooted.
Confirmed - I still have 'normal' audio, i.e. WinAmp, and YouTube both produce sound.
In SONAR, I cranked the ASIO buffer down to 64 samples.
 
It played back... which is unusual... but I was hearing crackles/static. Not so good. So I reset it back to 128 samples. Smooth playback.
 
Tentative judgement: It's improved. I haven't tried recording yet, but so far this seems to be better.
 
THANKS CRAIG!
 
(NB: Sound card is PCI-bus Echo Layla3G)

I have, under System Devices, an entry called "High Definition Audio Bus."  Disabling this removed  "AMD High Definition Audio Device" from Sound, video and game controllers. I hope I experience a similar boost....

I suggest disabling the onboard audio device in BIOS to remove the associated bits in the device manager before disabling anything else. I think it better to make to not exist rather than just disable.
 
And then follow THE CRAIG's advice to disable the audio device(s) (I had 2) found under the SYSTEM folder in the device manager. Restart again. Verify under SYSTEM, AUDIO devices, and at the top AUDIO INPUTS/OUTPUTS, that only the desired device is listed.  Disable any undesirable dudes. Restart again.
 
And then open the windows audio settings via the speaker control in the tray, and verify all settings for the playback and recording devices are correct: bit level,...
 
I always uncheck "Allow application to take exclusive control,..."  This may not be correct. But I "remember" audio not working unless an application had focus.
 
RJ
 
 

OK , I just got done experimenting with this info over here  .
After i disabled the Realtek High Def…Audio Driver and the High Definition Audio Device I was able to play back a few multi track projects w effects and have no glitches what so ever at 64 Samples during play back ….
X3 seemed fine with that 
I did have a few problems when I wanted to record my guitar at the 64 samples settings ...
in hindsight I probably should have used a different amp sim then the one i recorded with
I used The Vandal ( full version VST 2 ) and it crashed SONAR a few times on me ...
after raising the buffers I had no problem what so ever while in X3 ….using Vandal ...
 
Craig ,I would be curious to know if you happened to experience  any sort of problems with any of your non SONAR Windows Audio programs …..X3 ran nice , but I did experience a ton of lost ASIO buffers while using Samp…..
in about 20 seconds I hit a few thousand lost ASIO buffer errors ...
 
in any event I bumped up my sample buffers to 256 Samples and everything is working very smoothly all across the board..
 
as far as I'm concerned , I'm gonna keep the Realtek High Def…Audio Driver and the High Definition Audio Device disabled …
my modestly speced lap top is running much better than it was before the tweaks …. 
 
thanks, 
 
Kenny

Under Sound Video and Game Controllers, I have "High Definition Audio Device." Under System Devices, I have "High Definition Audio Controller." I disabled both, but the change made no noticeable performance difference for my system. My graphics card is an ATI Radeon HD 5770.
 
I'm OK with my audio interfaces' latency performance. I can run most heavy projects such as the SONAR demo projects (Cori Yarckin, ShiftyAndTheBigShots, etc.) with an 8.2 ms latency setting at 96 samples with my UltraLite MK3, but I have to raise the setting to 128 samples with 10.4 ms roundtrip latency to playback These Arms without crackles, pops, or dropouts, and with my Audigy 2 ZS Platinum Pro using the kX Project Audio Driver version 3552, I can run all the SONAR Demo Projects at 11.6 ms roundtrip latency setting or lower depending on which demo project. These Arms is the heaviest so I have to use the 11.6 ms roundtrip latency setting with 256 samples for that one.
 
I would like to have the ultra low latency performance of a RME interface, but I get by with what I have, for now.

These are interesting results. I knew it wouldn't affect all systems, but so far there are quite a few reports of improvements.
 
My current theory is that the graphics card audio driver interferes with some element that the interface driver has in common with it. Drivers like the ones for MOTU, RME, and Lynx, which are known to have lower-than-usual latency, may not be dependent on the same elements that cause the problem. This might also shed some light on why ASIO4ALL can wreak havoc with some drivers, because it's living in the same "world" as the usual interface drivers.
 
I dunno the theory, all I know is I'm really grateful I can run Sonar at dramatically lower latencies. Kenny, I'll check out some other programs but I can tell you Ableton Live works better now too. I'm also going to try Pro Tools at some point, because I always had lousy latency with it. Could hardly ever go below 512 except with the simplest projects.
 

Ugh I really envy OSX people sometimes. I hate parts of it, and really wouldn't want to switch away from Sonar, but the whole audio/midi part is just soooooo much better done.

Thanks for this find, Craig. I don't really have issues on my desktop but it seems worth checking if it could get better. I will definitely also try it in my laptop!

Sanderxpander
Ugh I really envy OSX people sometimes. I hate parts of it, and really wouldn't want to switch away from Sonar, but the whole audio/midi part is just soooooo much better done.

 
Yes, after so many years of getting it so wrong, Core Audio really got it right. WDM had real potential and allows for easy aggregating, but it doesn't seem like Microsoft cared all that much about optimizing it. 

Not to mention the ten MIDI devices limit, made worse by the fact that Windows sees the same device connected to a different bus as a new device. I've taken to uninstalling all drivers I'm not actually using and keeping a backup folder on my HD with device drivers I might need. On my laptop, I mean. If Windows 10 fixes this I'll be ecstatic, but I'm not holding my breath.

Hi Craig thank you for having this post.
 
There is another method to share just in case the driver comes back on again after a reboot. The following will permanently prevent HD Audio from Windows loading regardless be they from AMD, nVidia or Realtek.
 
***** WARNING ***** This is a registry hack.
 
HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\HDAudAddService - set Start to 4
HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\HDAudBus - set Start to 4
 
***** WARNING ***** This is a registry hack.
 
In my own time i have experimented with disabling Windows Audio and Windows Audio Endpoint Builder but that can only work halfway unfortunately. Programmes such as Sonar and Sound Forge, running on ASIO will work fine. However, programmes which inherently cannot and or do not use ASIO will not work; stuff like VLC and Media Monkey.