I want to debug one application with some GFLAGS options in 'WinDbg Preview' but I can't find gflags.exe in installation directories. and also I don't want to use windbg legacy for this and wanna switch to 'WinDbg Preview' According to the conference 'defcon27'
This features not implemented yet or what? and How can I set or unset global flags with that?
This features not implemented yet or what?
Exactly. Use the "legacy" version (which is still the official version, BTW. The other version is a preview, as the name says.).
If you don't want to install it, that's fine. Install it on a virtual machine and copy the installation directory. WinDbg is quite portable. Never had any issues with it. (In production debugging, you don't want to install software, so you run it from a USB stick. That BTW won't work with the "app" version as easy as before.)
How can I set or unset global flags with that?
You can't. Except for using the !gflag command (which is not equivalent to what you want).
I don't want to use windbg legacy for this
That's your personal choice and your personal problem then. You can implement your own version of GFlags, if you like. It's all about Registry keys being set, AFAIK.