its lags like grand maa in windows 10 fall creator update

I normally hate it when people say "it works for me" in answer to a question because it doesn't fix the problem,  But on this occasion I have to say it because it's true and relevant.

I don't get any lag at all.  The problem then becomes one of diagnosing why SnagIt should be so slow on your PC.  You may be better off raising a support ticket.

I don't know what version of SnagIt your using, but I would run a repair install of SnagIt.
You run it from the control panel. 
Repair installs can fix most issues, especially ones like these. "File Corruption"
If your running a version that only offers "Change" as an option in the control panel. Click that, another window will pop up, then you will select "Repair"
 


 Windows 10 fall update is a Big one. It took an hour to download and almost that long to install.

 It broke SnagIt 2018 on my machine,  it had to reinstall itself the first time I launched it after the update.

I run 2 color calibrated monitors, my primary monitors calibration had  became corrupted,  it's profile would no longer load.
 I had to recalibrate that monitor. That was 1/2 an hour of my life lost. 
 I just recalibrated them 2 days ago. Oh well.

I won't be surprised if there's more things broken, I'll deal with them as they pop up.

Regards,Joe 

  

Sir im using letest version of th snagit,