How to avoid META-Key captured by windows instead of emacs itself

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How to avoid META-Key captured by windows instead of emacs itself
I am a PC user and by defualt I like to use ALT key as the meta key
to
perform the various key-binding operations, but
when shift into Windows OS, the ALT key is captured by windows first
and then if the
key-binding is not defined in windows ,Alt-d for example ,it will pass
onto the emacs to process
,but if the  key are defined by windows itself,it will not delivery it
to the system,
Now, to avoid such situation,i need to to use ESC instead of alt key ,
its appears
ugly inconvinence,for it need to strok two key .