getting "Sonar not responding "  error for the past few months when saving projects, closing Sonar or even opening existing projects sometimes.  most times it eventually open or save but it takes up to 1 minute or more for the "Sonar not responding" error to clear. It also crashes Sonar very often when recording audio.  I only record 1 audio track at a time.  My project are midi and audio, no softsynths, just audio from my Ensoniq keyboard. crashes even with no plugins on any track.
 
 
I have uninstall, deleted files and download clean copy, roll back to previous months, I have the latest driver for audio interface and still have the problem.  I have turned off all unnecessary features in Windows.  
 
I got this Dell laptop last year, Windows 10, home, 64bit, Intel I5, core 6200, 2.30ghz, 16 ram.  probably slow hard drive but does anyone experience this?  Any tips or links on how to optimize Windows 10, and Sonar for Audio? help

Make sure you're using the latest driver for your audio interface,  and check your video drivers as well. The latest video driver may not be the best,  and win10 always updates my nvidia drivers. I use an older version that I keep handy to revert to. Also, disable any hdaudio devices in device manager are not your audio device… 

First run Latency Monitor. http://www.resplendence.com/latencymon
 
I know they've improved, in the past Behringer was very pour quality drivers  how old is the interface and are the asio drivers said to work with W 10? . 

Johnny brings up a good point about those Behringer interfaces.
In my travels, problems with saving projects is mainly due to 2 things:
audio interface and Hard drive. Sometimes it can be a driver conflict but often a Audio interface driver.