I had a problem yesterday.  I was working on mixing and all of a sudden Sonar would not recognize my keyboard and my Roland Studio-Capture.  It told me no audio device detected.  Closing and restarting Sonar was no help.  The keyboard was working in other Windows 10 applications and the Studio-Capture was still connected and the Studio Capture Control panel showed it connected and working. 
 
I've had several "glitches" with Sonar and Win 10 since the Ipswich upgrade and considering going back.   I also have Win 7 still installed (dual boot) and went to Win 7 and finished up my mixes without problems (using the Ipswich version).

Please check my previous post first. If no joy general advice is generally (no particular order)...

1) Update audio interface drivers and firmware to latest. I strongly recommend removing old version and rebooting afterwards. Then when new one is installed reset the settings everywhere on the interface.

2) Temp disable your virus scanner. Before you do that though scan for your system for viruses and malware. Ie with AVG and Malwarebytes.

3) Make sure your audio interface is disabled in windows control panel sounds

4) Make sure the interface is plugged in USB2 socket.

5) Defrag.

6) Update your display drivers

7) Update the rest of your drivers and firmware everywhere. eg controllers.

8) Disable unnecessary startup programs and services. Remove unnecessary applications from windows add/remove programs.

9) Update your motherboard chipset (try Intel driver update site) and BIOS

10) Check windows event viewer for bugs.

11) Try deleting AUD.INI (google for details)

12) Check windows device manager. Can you disable any drivers you don't need? eg HDMI drivers.

13) Check task scheduler to make sure nothing is running whilst using your DAW.

14) Make sure CPU in windows power settings is set to 100 - min/max. Optimize your drivers for power management.

15) If you have ASIO4ALL remove it!!!

16) Tools latencymon, process monitor and process explorer are your friends here.

17) Run windows update!

All my drivers are updated, including Intel chipset and CPU, I use the built in Windows Defender and have NEVER had an issue with that.  Latency Mon shows my system can handle real time data.  I DO NOT use ASIO4ALL, the Roland equipment has ASIO drivers. 
 
Sonar has been working OK, only change is the Ipswich updates.   

fireberd
All my drivers are updated, including Intel chipset and CPU, I use the built in Windows Defender and have NEVER had an issue with that.  Latency Mon shows my system can handle real time data.  I DO NOT use ASIO4ALL, the Roland equipment has ASIO drivers. 
 
Sonar has been working OK, only change is the Ipswich updates.   

Sorry I'm talking to the OP. If you have issues I suggest you start your own thread otherwise things will get confusing...

Thank you for the list of very good suggestions. I have custom built computer, so I am very aware of drivers, BIOS and other stuff. I would NOT recommend to anybody to downgrade back to Win 7. Eventually we all will be on Windows 10, Sonar updates will be tested on Win 10 and it will be better to stay with everybody and not being left behind. If there issues with Win 10, we need to work them out and move forward. I see no point in going back and make old OS catch up to the new features and updates that will be available.
 
3) Make sure your audio interface is disabled in windows control panel sounds

4) Make sure the interface is plugged in USB2 socket.

5) Defrag.
 
You mean my onboard sound card? Or my actual audio interface? My interface is FireWire, not USB. My motherboard sound card also enabled- when I watch videos or listen music- I use it. I dont have to have it enabled but it never caused problems in Win 8.
 
Nothing should be running other than Norton Antivirus. I had some issues with it giving me hundreds of false positives, especially Native Instruments- it hates NI! It was just deleting my Komplete stuff. So this thing can do anything it wants.
 
The dropouts- it happens if I try to mute/unmute takes, or just randomly with no playback... Will monitor.  

For diagnostic purposes try disabling all your audio interfaces in windows control panel sounds. For a more permanent solution you could just use your onboard soundcard in there (and route a cable from the output of the onboard sound into your audio interface). Sonar should continue to function as normal either way with your audio interface.
 
Also the HD audio driver from the display adapter (if you have one) is in device manager, just right click and disable that.

Please check post #4 (still need full feedback on this) and after trying that post #12, anyway and please keep us updated.
 
Thanks.

I always exclude Native Instruments ((where most of my sample libraries are) and Cakewalk-related folders from my antivirus program (Avast). and that really helps Sonar out.
 
Bob Bone
 

How is excluding NI helps Sonar?
 
I excluded it, but it founded it on the back up drive. It gives me like 50 false positives every time I start computer. This would be conversation for another thread.
 
I am reading about editing AUD.INI. What exactly kind of information will I lose if I delete this file? Will I have to reconfigure my screen settings? I dont have it saved in any templates- iut just always there when I start Sonar, but it took a while to adjust it to my liking...

There was a thread started here by me a while back about Windows 10 upgrade turned my internal audio drivers and sound controller back on! Check in the Device Manager and see if your internal sound card has been re-enabled. If so, dis-able. Do you know how to do that? I'll watch here for a response and if you don't, I will be happy to help.
If you do know how, look under System Devices and dis-able the HD Audio Controller. That will take the internal sound device completely off line, drivers and all. That one step has helped me get my latency down to almost nothing.
 

It been always on, never caused latency or drop outs.

vladasyn
I am reading about editing AUD.INI. What exactly kind of information will I lose if I delete this file? Will I have to reconfigure my screen settings? I dont have it saved in any templates- iut just always there when I start Sonar, but it took a while to adjust it to my liking...

 
It just resets what is in Sonar Preferences.
Just back up the old one if you are worried about it.